Gridcoin - The Good

In this post we will take an in depth look at the cryptocurrency Gridcoin, we show how we found two critical design vulnerabilities and how we fixed them.

In the last past years we saw many scientific publications about cryptocurrencies. Some focused on theoretical parts [Source] and some on practical attacks against specific well-known cryptocurrencies, like Bitcoin [Source]. But in general there is a lack of practical research against alternative coins. Or did you know that there are currently over 830 currencies listed online? So we asked ourselves how secure are these currencies, and if they are not just re-branded forks of the Bitcoin source code?

Background

Gridcoin is an Altcoin, which is in active development since 2013. It claims to provide a high sustainability, as it has very low energy requirements in comparison to Bitcoin. It rewards users for contributing computation power to scientific projects, published on the BOINC project platform. Although Gridcoin is not as widespread as Bitcoin, its draft is very appealing as it attempts to eliminate Bitcoin's core problems. It possesses a market capitalization of $13,719,142 (2017/08/10).

Berkeley Open Infrastructure for Network Computing

To solve general scientific meaningful problems, Gridcoin draws on the well-known Berkeley Open Infrastructure for Network Computing (BOINC). It is a software platform for volunteer computing, initially released in 2002 and developed by the University of California, Berkeley. It is an open source software licensed under the GNU Lesser General Public License. The platform enables professionals in need for computation power to distribute their tasks to volunteers. Nowadays it is widely used by researchers with limited resources to solve scientific problems, for example, healing cancer, investigate global warming, finding extraterrestrial intelligence in radio signals and finding larger prime numbers.
When launching a BOINC project, its maintainer is required to set up his own BOINC server. Project volunteers may then create accounts (by submitting a username, a password and an email address) and work on specific project tasks, called workunits. The volunteers can process the project tasks and transfer their solutions with a BOINC client.

BOINC architecture

BOINC uses a client-server architecture to achieve its rich feature set. The server component handles the client requests for workunits and the problem solutions uploaded by the clients. The solutions are validated and assimilated by the server component. All workunits are created by the server component and each workunit represents a chunk of a scientific problem which is encapsulated into an application. This application consists of one or multiple in-/output files, containing binary or ASCII encoded parameters.

BOINC terminology

• iCPID
• The BOINC project server creates the internal Cross Project Identifier (iCPID) as a 16 byte long random value during account creation. This value is stored by the client and server. From this time on, the iCPID is included in every request and response between client and server
• eCPID
• The external Cross Project Identifier (eCPID) serves the purpose of identifying a volunteer across different BOINC projects without revealing the corresponding email address. It is computed by applying the cryptographic hash function MD5 to (iCPID,email) and thus has a length of 16 byte [Source].

eCPID = MD5(iCPID||email)

• Credits
• BOINC credits are generated whenever a host submits a solution to an assigned task. They are measured in Cobblestone, whereas one Cobblestone is equivalent to 1/200 of CPU time on a reference machine with 1,000 mega floating point operation per seconds [Source]
• Total Credit
• Total number of Cubblestones a user invested with his machines for scientific computations
• Recent Average Credit (RAC)
• RAC is defined as the average number of Cobblestones per day generated recently [Source]. If an entire week passes, the value is divided by two. Thus old credits are weakly weighted. It is recalculated whenever a host generates credit [Source].

Gridcoin

As a fork of Litecoin, Gridcoin-Research is a blockchain based cryptocurrency and shares many concepts with Bitcoin. While Bitcoin's transaction data structure and concept is used in an unmodified version, Gridcoin-Research utilizes a slightly modified block structure. A Gridcoin-Research block encapsulates a header and body. The header contains needed meta information and the body encloses transactions. Due to the hashPrevBlockHeader field, which contains the hash of the previous block-header, the blocks are linked and form the distributed ledger, the blockchain. Blocks in the blockchain are created by so called minters. Each block stores a list of recent transactions in its body and further metadata in its header. To ensure that all transactions are confirmed in a decisive order, each block-header field contains a reference to the previous one. To regulate the rate in which new blocks are appended to the blockchain and to reward BOINC contribution, Gridcoin-Research implements another concept called Proof-of-Research. Proof-of-Research is a combination of a new overhauled Proof-of-BOINC concept, which was originally designed for Gridcoin-Classic and the improved Proof-of-Stake concept, inspired by alternative cryptocurrencies.

Fig. 1: Gridcoin block structure

Gridcoin terminology

In order to understand the attacks we need to introduce some Gridcoin specific terms.

• eCPID
• Identifier value from BOINC used in Gridcoin to identify the researcher.
• CPIDv2
• contains a checksum to prove that the minter is the owner of the used eCPID. We fully describe the content of this field in the last attack section.
• GRCAddress
• contains the payment address of the minter.
• ResearchAge
• is defined as the time span between the creation time of the last Proof-of-Research generated block with the user's eCPID and the time stamp of the last block in the chain measured in days.
• RSAWeight
• estimates the user's Gridcoin gain for the next two weeks, based on the BOINC contribution of the past two weeks.

Proof-of-Stake

Proof-of-Stake is a Proof-of-Work replacement, which was first utilized by the cryptocurrency Peercoin in 2012. This alternative concept was developed to showcase a working Bitcoin related currency with low power consumption. Therefore, the block generation process has been overhauled. To create a new valid block for the Gridcoin blockchain the following inequality have to be satisfied:

SHA256(SHA256(kernel)) < Target * UTXO Value + RSAWeight

The kernel value represents the concatenation of the parameters listed in Table 2. The referenced unspent transaction output (UTXO) must be at least 16 hours old. The so called RSAWeight is an input value to the kernel computation, it's indicates the average BOINC work, done by a Gridcoin minter.
In direct comparison to Bitcoin's Proof-of-Work concept, it is notable that the hash of the previous block-header is not part of the kernel. Consequently, it is theoretically possible to create a block at any previous point in time in the past. To prevent this, Gridcoin-Research creates fixed interval checkpoint blocks. Once a checkpoint block is synchronized with the network, blocks with older time stamps became invalid. Considering the nature of the used kernel fields, a client with only one UTXO is able to perform a hash calculation each time nTime is updated. This occurs every second, as nTime is a UNIX time stamp. To be able to change the txPrev fields and thereby increase his hash rate, he needs to gain more UTXO by purchasing coins. Note that high UTXO and RSAWeight values mitigate the difficulty of the cryptographic puzzle, which increase the chance of finding a valid kernel. RSAWeight was explained above. Once a sufficient kernel has been found, the referenced UTXO is spent in a transaction to the creator of the block and included in the generated block. This consumes the old UTXO and generates a new one with the age of zero.

The Gridcoin-Research concept does not require much electrical power, because the maximum hash rate of an entity is limited by its owned amount of UTXOs with suitable age.

Proof-of-Research

Minters relying solely on the Proof-of-Stake rewards are called Investors. In addition to Proof-of-Stake, Gridcoin gives minters a possibility to increase their income with Proof-of-Research rewards. The Proof-of-Research concept implemented in Gridcoin-Research allows the minters to highly increase their block reward by utilizing their BOINC Credits. In this case the minter is called a Researcher.
To reward BOINC contribution, relevant BOINC data needs to be stored in each minted block. Therefore, the software uses the BOINCHash data structure, which is encapsulated in the first transaction of each block. The structure encloses the fields listed in Table 6. The minting and verification process is shown in Figure 2 and works as follows:

1. A minter (Researcher) participates in a BOINC project A and performs computational work for it. In return the project server increases the users Total Credit value on the server. The server therefore stores the minter's email address, iCPID, eCPID and RAC.
2. Statistical websites contact project server and down-load the statistics for all users from the project server (A).
3. After the user earns credits, his RAC increases. Consequently, this eases the finding of a solution for the Proof-of-Stake cryptographic puzzle, and the user can create (mint) a block and broadcast it to the Gridcoin network.
4. Another minter (Investor or Researcher) will receive the block and validate it. Therefore, he extracts the values from the BOINCHash data structure inside the block.
5. The minter uses the eCPID from the BOINCHash to request the RAC and other needed values from a statistical website and compares them to the data extracted from the BOINCHash structure, in the event that they are equal and the block solves the cryptographic puzzle, the block is accepted.

 Fig. 2: Gridcoin architecture and minting process

Reward calculation

The total reward for a solved block is called the Subsidy and is computed as the sum of the Proof-of-Research and the Proof-of-Stake reward.

If a minter operates as an Investor (without BOINC contribution), the eCPID is set to the string Investor and all other fields of the BOINCHash are zeroed. An Investor receives only a relatively small Proof-of-Stake reward.
Because the Proof-of-Research reward is much higher than its Proof-of-Stake counterpart, contributing to BOINC projects is more worth the effort.

Statistic Website

At the beginning of the blog post, the core concept behind BOINC was described. One functionality is the creation of BOINC Credits for users, who perform computational work for the project server. This increases the competition between BOINC users and therefore has a positive effect on the amount of computational work users commit. Different websites 4 collect credit information of BOINC users from known project servers and present them online. The Gridcoin client compares the RAC and total credit values stored in a new minted block with the values stored on cpid.gridcoin.us:5000/get_user.php?cpid=eCPID where eCPID is the actual value of the researcher. If there are differences, the client declines the block. In short, statistical websites are used as control instance for Gridcoin. It is obvious that gridcoin.us administrators are able to modify values of any user. Thus, they are able to manipulate the amount of Gridcoins a minter gets for his computational work. This is crucial for the trust level and undermines the general decentralized structure of a cryptocurrency.

Project Servers

Gridcoin utilizes BOINC projects to outsource meaningful computation tasks from the currency. For many known meaningful problems there exist project servers 5 that validate solutions submitted by users, 6 and decide how many credits the users receive for their solutions. Therefore, the project servers can indirectly control the amount of Gridcoins a minter gets for his minted block via the total credit value. As a result, a Gridcoin user also needs to trust the project administrators. This is very critical since there is no transparency in the credit system of project server. If you want to know why decentralization is not yet an option, see our paper from WOOT'17.

Attacks

In addition to the trust a Gridcoin user needs to put into the project server and statistic website administrators, Gridcoin suffers from serious flaws which allows the revelation of minter identities or even stealing coins. Our attacks do not rely on the Gridcoin trust issues and the attacker does not need to be in possession of specific server administrative rights. We assume the following two simple attackers with limited capability sets. The first one, is the blockchain grabber which can download the Gridcoin blockchain from an Internet resource and runs a program on the downloaded data. The second one, the Gridcoin attacker, acts as a normal Gridcoin user, but uses a modified Gridcoin client version, in order to run our attacks.

Interestingly, the developer of Gridcoin tried to make the source code analysis somewhat harder, by obfuscating the source code of relevant functions.

 Fig. 3: Obfuscated source code in Gridcoin [Source]

Grab Gridcoin user email addresses

In order to protect the email addresses of Gridcoin Researchers, neither BOINC project websites nor statistical websites directly include these privacy critical data. The statistical websites only include eCPID entries, which are used to reward Gridcoin Researchers. However, the email addresses are hidden inside the computation of the BOINCHash (cf. Table 1). A BOINCHash is created every time a Researcher mints a new block and includes a CPIDv2 value. The CPIDv2 value contains an obfuscated email address with iCPID and a hash over the previous blockchain block.

By collecting the blockchain data and reversing the obfuscation function (cf. Figure 4 and Figure 7), the attacker gets all email addresses and iCPIDs ever used by Gridcoin Researchers. See the reversed obfuscation function in Figure 4 and Figure 5.

Evaluation

We implemented a deobfuscation function (cf. Figure 7) and executed it on the blockchain. This way, we were able to retrieve all (2709) BOINC email addresses and iCPIDs used by Gridcoin Researchers. This is a serious privacy issue and we address it with our fix (cf. The Fix).

Steal Gridcoin users BOINC reward

The previous attack through deobfuscation allows us to retrieve iCPID values and email addresses. Thus, we have all values needed to create a new legitimate eCPID. This is required because the CPIDv2 contains the last block hash and requires a re-computation for every new block it should be used in. We use this fact in the following attack and show how to steal the computational work from another legitimate Gridcoin Researcher by mining a new Gridcoin block with forged BOINC information. Throughout this last part of the post, we assume the Gridcoin Minter attacker model where the attacker has a valid Gridcoin account and can create new blocks. However, the attacker does not perform any BOINC work.

 Tab. 1: BOINCHash structure as stored and used in the Gridcoin blockchain.

As stated at the beginning of the blog post, the pre-image of the eCPID is stored obfuscated in every Gridcoin block, which contains a Proof-of-Research reward. We gathered one pre-image from the minted blocks of our victim and deobfuscated it. Thus, we know the values of the iCPID, and the email address of our victim. Subsequently, use the hash of the last block created by the network and use these three values to create a valid CPIDv2. Afterwards we constructed a new block. In the block we also store the current BOINC values of our victim, which we can gather from the statistics websites. The final block is afterwards sent into the Gridcoin network. In case all values are computed correctly by the attacker, the network will accept the block, and resulting in a higher reward for the attacker, consisting of Proof-of-Stake and Proof-of-Research reward.

 Fig. 4: Obfuscation function

 Fig. 5: Deobfuscation function

Evaluation

In order to verify our attacks practically, we created two virtual machines (R and A), both running Ubuntu 14.04.3 LTS. The virtual machine R contained a legitimate BOINC and Gridcoin instance. It represented the setup of a normal Gridcoin Researcher. The second machine A contained a modified Gridcoin-Research client 3.5.6.8 version, which tried to steal the Proof-of-Research reward of virtual machine R. Thus, we did not steal reward of other legitimate users. The victim BOINC client was attached to the SETI@home project 11 with the eCPID 9f502770e61fc03d23d8e51adf7c6291.

The victim and the attacker were in possession of Gridcoins, enabling them to stake currency and to create new blocks.

 Fig. 6: CPIDv2 calculation deobfuscated

Initially both Gridcoin-Research clients retrieved the blockchain from other Gridcoin nodes in the Gridcoin network.

The Gridcoin attack client made it possible to specify the victim email address, iCPID and target project. All these values can be retrieved from the downloaded blockchain and our previous attack via the reverseCPIDv2 function as shown in Figure 7. The attack client read the iCPID and email address of the victim from a modified configuration file. All other values, for example, RAC or ResearchAge, were pulled from http://cpid.gridcoin.us:5000/get_user.php?cpid=. As soon as all values were received, the client attempted to create a new valid block.

 Fig. 7: Reverse the CPIDv2 calculation to get iCPID and email address

Once a block had been created and confirmed, the attacker received the increased coin reward with zero BOINC contribution done. The attack could only be detected by its victims because an outside user did not know the legitimate Gridcoin addresses a Researcher uses.

All blocks created with our victim's eCPID are shown in Table 2. Illegitimate blocks are highlighted. We were able to mint multiple illegitimate blocks, and thus stealing Research Age from our victim machine R. All nine blocks created and send by our attacker to the Gridcoin network passed the Gridcoin block verification, were confirmed multiple times, and are part of the current Gridcoin blockchain. During our testing timespan of approximately three weeks, the attacker machine was wrongfully rewarded with 72.4 Proof-of-Research generated Gridcoins, without any BOINC work. The results show that the attack is not only theoretically possible, but also very practical, feasible and effective. The attack results can be reproduced with our Gridcoin-Research-Attack client.

 Tab. 2:Blocks minted with the victim's eCPID

The Fix

In order to fix the security issue, we found one solution which does not require any changes to the BOINC source code nor the infrastructure. It is sufficient to change some parts of the already existing Gridcoin Beacon system. Thus, our solution is backwards compatible.
The current Gridcoin client utilizes so called Beacons to register new eCPIDs and stores them as a transaction of 0.0001 Gridcoins in a Superblock which is created every 24 hours. A Beacon encloses the user's personal eCPIDs, a corresponding unused (but irreversible) CPIDv2, and the wallet's main Gridcoin payment address. Once the Superblock is created, the eCPIDs is bound to one Gridcoin payment address. During the block verification process this bond is unfortunately not checked. Furthermore, the existing Beacon system does not use any strong asymmetric cryptography to ensure authenticity and integrity of the broadcasted data. We propose to extend the Beacon system with public key cryptography. In detail, we suggest that a user binds his fresh public key PK_1 to a newly generated eCPID, and then storing them together in a Superblock. An initial Beacon would therefore contain a hashed (e.g. SHA-256) eCPID, the public key, a Nonce, and a cryptographic signature created with the corresponding secret key SK_1 of the public key. This allows only the owner of the secret key to create valid signatures over blocks created with his eCPID. Thus, an adversary first needs to forge a cryptographic signature before he can claim Proof-of-Research work of another Gridcoin user. Thus, he is not capable of stealing the reward of the user.

Beacon to create a eCPID, public/secret key pair bond

For verification purposes nodes fetch the corresponding latest public key from one of the Superblocks. Furthermore, this Beacon structure allows a user to replace his previous public key associated with his eCPID. This is realized by submitting a new Beacon with a new public key PK_2, signed with his old secret key.

Beacon to update a eCPID, public/secret key pair bond

All Beacons in the chain are verifiable and the latest public key is always authentic. The Nonce provide freshness for the signature input, and therefore prevent replay attacks against the Beacon system.
Note that the eCPID needs to be completely unknown to the network, when sending the initial Beacon, for this concept to work as intended. The hash function ensures, that the Beacon does not reveal the fresh eCPID. As a result, an attacker is unable to mint with a eCPID even if he was able to intercept an initial Beacon and replaced the public key and signature with his own parameters, beforehand. This solution does not require any changes in the BOINC source code or the project servers.

Sign a block

In order to claim the Proof-of-Research reward for a newly created block, the Gridcoin minter computes a signature over the hash of the blockheader. Afterwards, he stores the resulting value at the end of the corresponding block in a new field. The private key used for the signature generation must correspond to the advertised public key by the user. It is important to note that the signature value is not part of the Merkle tree, and thus does not change the blockheader. In the end, the signature can then be verified by every other Gridcoin user via the advertised public key corresponding to the eCPID of the Gridcoin minter.

Responsible Disclosure

The attacks and the countermeasures were responsibly disclosed to the Gridcoin developer on the 14th of September, 2016. The developer used our proposed countermeasures and started to implement a new version. Since version 3.5.8.8, which is mandatory for all Gridcoin users, there exists an implementation, which contains countermeasures to our reward stealing attack.
See our next blog post, why Gridcoin is still insecure and should not be used anymore.

Further Reading

A more detailed description of Gridcoin and the attacks will be presented at WOOT'17, the paper is available here.

Authors

Tobias Niemann

Juraj Somorovsky

Martin Grothe

Continue reading

• Hacker Significado
• Growth Hacking
• Como Empezar A Hackear
• Hacking Videos
• Hacking Background
• Hacking Informatico

Hacktivity 2018 Badge - Quick Start Guide For Beginners

You either landed on this blog post because 

• you are a huge fan of Hacktivity
• you bought this badge around a year ago
• you are just interested in hacker conference badge hacking. 

or maybe all of the above. Whatever the reasons, this guide should be helpful for those who never had any real-life experience with these little gadgets. 

But first things first, here is a list what you need for hacking the badge:

• a computer with USB port and macOS, Linux or Windows. You can use other OS as well, but this guide covers these
• USB mini cable to connect the badge to the computer
• the Hacktivity badge from 2018

By default, this is how your badge looks like.

Let's get started

Luckily, you don't need any soldering skills for the first steps. Just connect the USB mini port to the bottom left connector on the badge, connect the other part of the USB cable to your computer, and within some seconds you will be able to see that the lights on your badge are blinking. So far so good. 

Now, depending on which OS you use, you should choose your destiny here.

Linux

The best source of information about a new device being connected is

# dmesg

The tail of the output should look like

[267300.206966] usb 2-2.2: new full-speed USB device number 14 using uhci_hcd
[267300.326484] usb 2-2.2: New USB device found, idVendor=0403, idProduct=6001
[267300.326486] usb 2-2.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[267300.326487] usb 2-2.2: Product: FT232R USB UART
[267300.326488] usb 2-2.2: Manufacturer: FTDI
[267300.326489] usb 2-2.2: SerialNumber: AC01U4XN
[267300.558684] usbcore: registered new interface driver usbserial_generic
[267300.558692] usbserial: USB Serial support registered for generic
[267300.639673] usbcore: registered new interface driver ftdi_sio
[267300.639684] usbserial: USB Serial support registered for FTDI USB Serial Device
[267300.639713] ftdi_sio 2-2.2:1.0: FTDI USB Serial Device converter detected
[267300.639741] usb 2-2.2: Detected FT232RL
[267300.643235] usb 2-2.2: FTDI USB Serial Device converter now attached to ttyUSB0

Dmesg is pretty kind to us, as it even notifies us that the device is now attached to ttyUSB0. 

From now on, connecting to the device is exactly the same as it is in the macOS section, so please find the "Linux users, read it from here" section below. 

macOS

There are multiple commands you can type into Terminal to get an idea about what you are looking at. One command is:

# ioreg -p IOUSB -w0 -l

With this command, you should get output similar to this:

+-o FT232R USB UART@14100000  <class AppleUSBDevice, id 0x100005465, registered, matched, active, busy 0 (712 ms), retain 20>
    |   {
    |     "sessionID" = 71217335583342
    |     "iManufacturer" = 1
    |     "bNumConfigurations" = 1
    |     "idProduct" = 24577
    |     "bcdDevice" = 1536
    |     "Bus Power Available" = 250
    |     "USB Address" = 2
    |     "bMaxPacketSize0" = 8
    |     "iProduct" = 2
    |     "iSerialNumber" = 3
    |     "bDeviceClass" = 0
    |     "Built-In" = No
    |     "locationID" = 336592896
    |     "bDeviceSubClass" = 0
    |     "bcdUSB" = 512
    |     "USB Product Name" = "FT232R USB UART"
    |     "PortNum" = 1
    |     "non-removable" = "no"
    |     "IOCFPlugInTypes" = {"9dc7b780-9ec0-11d4-a54f-000a27052861"="IOUSBFamily.kext/Contents/PlugIns/IOUSBLib.bundle"}
    |     "bDeviceProtocol" = 0
    |     "IOUserClientClass" = "IOUSBDeviceUserClientV2"
    |     "IOPowerManagement" = {"DevicePowerState"=0,"CurrentPowerState"=3,"CapabilityFlags"=65536,"MaxPowerState"=4,"DriverPowerState"=3}
    |     "kUSBCurrentConfiguration" = 1
    |     "Device Speed" = 1
    |     "USB Vendor Name" = "FTDI"
    |     "idVendor" = 1027
    |     "IOGeneralInterest" = "IOCommand is not serializable"
    |     "USB Serial Number" = "AC01U4XN"
    |     "IOClassNameOverride" = "IOUSBDevice"
    |   } 

The most important information you get is the USB serial number - AC01U4XN in my case.
Another way to get this information is

# system_profiler SPUSBDataType

which will give back something similar to:

FT232R USB UART:

          Product ID: 0x6001
          Vendor ID: 0x0403  (Future Technology Devices International Limited)
          Version: 6.00
          Serial Number: AC01U4XN
          Speed: Up to 12 Mb/sec
          Manufacturer: FTDI
          Location ID: 0x14100000 / 2
          Current Available (mA): 500
          Current Required (mA): 90
          Extra Operating Current (mA): 0

The serial number you got is the same.

What you are trying to achieve here is to connect to the device, but in order to connect to it, you have to know where the device in the /dev folder is mapped to. A quick and dirty solution is to list all devices under /dev when the device is disconnected, once when it is connected, and diff the outputs. For example, the following should do the job:

ls -lha /dev/tty* > plugged.txt
ls -lha /dev/tty* > np.txt
vimdiff plugged.txt np.txt

The result should be obvious, /dev/tty.usbserial-AC01U4XN is the new device in case macOS. In the case of Linux, it was /dev/ttyUSB0.

Linux users, read it from here. macOS users, please continue reading

Now you can use either the built-in screen command or minicom to get data out from the badge. Usually, you need three information in order to communicate with a badge. Path on /dev (you already got that), speed in baud, and the async config parameters. Either you can guess the speed or you can Google that for the specific device. Standard baud rates include 110, 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 38400, 57600, 115200, 128000 and 256000 bits per second. I usually found 1200, 9600 and 115200 a common choice, but that is just me.
Regarding the async config parameters, the default is that 8 bits are used, there is no parity bit, and 1 stop bit is used. The short abbreviation for this is 8n1. In the next example, you will use the screen command. By default, it uses 8n1, but it is called cs8 to confuse the beginners.

If you type:
# screen /dev/tty.usbserial-AC01U4XN 9600
or
# screen /dev/ttyUSB0 9600
and wait for minutes and nothing happens, it is because the badge already tried to communicate via the USB port, but no-one was listening there. Disconnect the badge from the computer, connect again, and type the screen command above to connect. If you are quick enough you can see that the amber LED will stop blinking and your screen command is greeted with some interesting information. By quick enough I mean ˜90 seconds, as it takes the device 1.5 minutes to boot the OS and the CTF app.

Windows

When you connect the device to Windows, you will be greeted with a pop-up.

Just click on the popup and you will see the COM port number the device is connected to:

In this case, it is connected to COM3. So let's fire up our favorite putty.exe, select Serial, choose COM3, add speed 9600, and you are ready to go!

You might check the end of the macOS section in case you can't see anything. Timing is everything.

The CTF

Welcome to the Hacktivity 2018 badge challenge!

This challenge consists of several tasks with one or more levels of
difficulty. They are all connected in some way or another to HW RE
and there's no competition, the whole purpose is to learn things.

Note: we recommend turning on local echo in your terminal!
Also, feel free to ask for hints at the Hackcenter!

Choose your destiny below:

  1. Visual HW debugging
  2. Reverse engineering
  3. RF hacking
  4. Crypto protection

Enter the number of the challenge you're interested in and press [

Excellent, now you are ready to hack this! In case you are lost in controlling the screen command, go to https://linuxize.com/post/how-to-use-linux-screen/.

I will not spoil any fun in giving out the challenge solutions here. It is still your task to find solutions for these.

But here is a catch. You can get a root shell on the device. And it is pretty straightforward. Just carefully remove the Omega shield from the badge. Now you see two jumpers; by default, these are connected together as UART1. As seen below.

But what happens if you move these jumpers to UART0? Guess what, you can get a root shell! This is what I call privilege escalation on the HW level :) But first, let's connect the Omega shield back. Also, for added fun, this new interface speaks on 115200 baud, so you should change your screen parameters to 115200. Also, the new interface has a different ID under /dev, but I am sure you can figure this out from now on.

If you connect to the device during boot time, you can see a lot of exciting debug information about the device. And after it boots, you just get a root prompt. Woohoo! 

But what can you do with this root access? Well, for starters, how about running 

# strings hello | less

From now on, you are on your own to hack this badge. Happy hacking.

Big thanks to Attila Marosi-Bauer and Hackerspace Budapest for developing this badge and the contests.

PS: In case you want to use the radio functionality of the badge, see below how you should solder the parts to it. By default, you can process slow speed radio frequency signals on GPIO19. But for higher transfer speeds, you should wire the RF module DATA OUT pin with the RX1 free together.

Continue reading

• Hacking Time
• Hacker Profesional
• Hacking Movies
• Python Hacking
• Growth Hacking Definicion
• Curso Hacker
• Body Hacking
• Que Hace Un Hacker
• Hacking Food
• Growth Hacking Barcelona
• Hacking School
• Pagina Hacker
• El Mejor Hacker Del Mundo
• Hacking Ético Con Herramientas Python Pdf
• Hacking Growth Pdf

Samurai: Web Testing Framework

"The Samurai Web Testing Framework is a live linux environment that has been pre-configured to function as a web pen-testing environment. The CD contains the best of the open source and free tools that focus on testing and attacking websites. In developing this environment, we have based our tool selection on the tools we use in our security practice. We have included the tools used in all four steps of a web pen-test." read more...

Website: http://samurai.inguardians.com

Related word

• Master Hacking Etico
• Penetration Testing A Hands-On Introduction To Hacking
• Hacking To The Gate
• Hacking Etico Curso Gratis
• Hacker Pelicula
• Manual Del Hacker
• Hacking Netflix Account
• Hacking Etico Que Es
• Curso Hacking Etico
• Hacking With Arduino

TERMINOLOGIES OF ETHICAL HACKING

What is the terminologies in ethical hacking?

Here are a few key terms that you will hear in discussion about hackers and what they do:

1-Backdoor-A secret pathway a hacker uses to gain entry to a computer system.

2-Adware-It is the softw-are designed to force pre-chosen ads to display on your system.

3-Attack-That action performs by a attacker on a system to gain unauthorized access.

4-Buffer Overflow-It is the process of attack where the hacker delivers malicious commands to a system by overrunning an application buffer.

5-Denial-of-Service attack (DOS)-A attack designed to cripple the victim's system by preventing it from handling its normal traffic,usally by flooding it with false traffic.

6-Email Warm-A virus-laden script or mini-program sent to an unsuspecting victim through a normal-looking email message.

7-Bruteforce Attack-It is an automated and simplest kind of method to gain access to a system or website. It tries different combination of usernames and passwords,again & again until it gets in from bruteforce dictionary.

8-Root Access-The highest level of access to a computer system,which can give them complete control over the system.

9-Root Kit-A set of tools used by an intruder to expand and disguise his control of the system.It is the stealthy type of software used for gain access to a computer system.

10-Session Hijacking- When a hacker is able to insert malicious data packets right into an actual data transmission over the internet connection.

11-Phreaker-Phreakers are considered the original computer hackers who break into the telephone network illegally, typically to make free longdistance phone calls or to tap lines.

12-Trojan Horse-It is a malicious program that tricks the computer user into opening it.There designed with an intention to destroy files,alter information,steal password or other information.

13-Virus-It is piece of code or malicious program which is capable of copying itself has a detrimental effect such as corrupting the system od destroying data. Antivirus is used to protect the system from viruses.

14-Worms-It is a self reflicating virus that does not alter  files but resides in the active memory and duplicate itself.

15-Vulnerability-It is a weakness which allows a hacker to compromise the security of a computer or network system to gain unauthorized access.

16-Threat-A threat is a possible danger that can exploit an existing bug or vulnerability to comprise the security of a computer or network system. Threat is of two types-physical & non physical.

17-Cross-site Scripting-(XSS) It is a type of computer security vulnerability found in web application.It enables attacker to inject client side script into web pages viwed by other users.

18-Botnet-It is also known as Zombie Army is a group of computers controlled without their owner's knowledge.It is used to send spam or make denial of service attacks.

19-Bot- A bot is a program that automates an action so that it can be done repeatedly at a much higher rate for a period than a human operator could do it.Example-Sending HTTP, FTP oe Telnet at a higer rate or calling script to creat objects at a higher rate.

20-Firewall-It is a designed to keep unwanted intruder outside a computer system or network for safe communication b/w system and users on the inside of the firewall.

21-Spam-A spam is unsolicited email or junk email sent to a large numbers of receipients without their consent.

22-Zombie Drone-It is defined as a hi-jacked computer that is being used anonymously as a soldier or drone for malicious activity.ExDistributing Unwanted Spam Emails.

23-Logic Bomb-It is a type of virus upload in to a system that triggers a malicious action when certain conditions are met.The most common version is Time Bomb.

24-Shrink Wrap code-The process of attack for exploiting the holes in unpatched or poorly configured software.

25-Malware-It is an umbrella term used to refer a variety of intrusive software, including computer viruses,worms,Trojan Horses,Ransomeware,spyware,adware, scareware and other malicious program.

Follow me on instagram-anoymous_adi

Related word

1. Libro Hacking Etico
2. Hacking Cracking
3. Hacking Websites
4. Hacking Social
5. Hacking Definicion
6. Curso De Hacking Etico
7. Libro Hacking Etico
8. Hacking Iphone
9. Significado De Hacker
10. Sean Ellis Growth Hacking
11. Linux Hacking Distro
12. Aprender Seguridad Informatica
13. Web Hacking 101

5 BEST HACKING BOOKS 2018

Most of the people don't go with videos and read books for learning. Book reading is a really effective way to learn and understand how things work. There are plenty of books about computers, security, penetration testing and hacking. Every book shows a different angle how things work and how to make system secure and how it can be penetrated by hackers. So, here I have gathered a few of the best hacking books of 2018 available on the market.

BEST HACKING BOOKS OF 2018

There are hundreds of books about hacking, but I have streamlined few of best hacking books of 2018.

1. THE HACKER'S PLAYBOOK PRACTICAL GUIDE TO PENETRATION

This handbook is about experting yourself with the hacking techniques in the hacker's way. This is about penetration testing that how hackers play their techniques and how we can counter them.

CONTENTS

• Introduction
• Pregame – The Setup
• Setting Up a Penetration Testing Box
• Before the Snap – Scanning the Network
• The Drive – Exploiting Scanner Findings
• The Throw – Manual Web Application Findings
• The Lateral Pass – Moving Through the Network
• The Screen – Social Engineering
• The Onside Kick – Attacks that Require Physical Access
• The Quarterback Sneak – Evading AV
• Special Teams – Cracking, Exploits, Tricks
• Post Game Analysis – Reporting

Download the Hacker's Playbook Practical Guide to Penetration.

2. ANDROID HACKER'S HANDBOOK

The Android Hacker's Handbook is about how the android devices can be hacked. Authors chose to write this book because the field of mobile security research is so "sparsely charted" with disparate and conflicted information (in the form of resources and techniques).

CONTENTS

• Chapter 1 Looking at the Ecosystem
• Chapter 2 Android Security Design and Architecture
• Chapter 3 Rooting Your Device
• Chapter 4 Reviewing Application Security
• Chapter 5 Understanding Android's Attack Surface
• Chapter 6 Finding Vulnerabilities with Fuzz Testing
• Chapter 7 Debugging and Analyzing Vulnerabilities
• Chapter 8 Exploiting User Space Software
• Chapter 9 Return Oriented Programming
• Chapter 10 Hacking and Attacking the Kernel
• Chapter 11 Attacking the Radio Interface Layer
• Chapter 12 Exploit Mitigations
• Chapter 13 Hardware Attacks

Download Android Hacker's Handbook.

3. PENETRATION TESTING: A HANDS-ON INTRODUCTION TO HACKING

This book is an effective practical guide to penetration testing tools and techniques. How to penetrate and hack into systems. This book covers beginner level to highly advanced penetration and hacking techniques.

CONTENTS

• Chapter 1: Setting Up Your Virtual Lab
• Chapter 2: Using Kali Linux
• Chapter 3: Programming
• Chapter 4: Using the Metasploit Framework
• Chapter 5: Information Gathering
• Chapter 6: Finding Vulnerabilities
• Chapter 7: Capturing Traffic
• Chapter 8: Exploitation
• Chapter 9: Password Attacks
• Chapter 10: Client-Side Exploitation
• Chapter 11: Social Engineering
• Chapter 12: Bypassing Antivirus Applications
• Chapter 13: Post Exploitation
• Chapter 14: Web Application Testing
• Chapter 15: Wireless Attacks
• Chapter 16: A Stack-Based Buffer Overflow in Linux
• Chapter 17: A Stack-Based Buffer Overflow in Windows
• Chapter 18: Structured Exception Handler Overwrites
• Chapter 19: Fuzzing, Porting Exploits, and Metasploit Modules
• Chapter 20: Using the Smartphone Pentesting Framework

Download Penetration Testing: A Hands-On Introduction To Hacking.

4. THE SHELLCODER'S HANDBOOK

This book is about learning shellcode's of the OS and how OS can be exploited. This book is all about discovering and exploiting security holes in devices to take over.

Authors: Chris Anley, John Heasman, Felix "FX" Linder, Gerardo Richarte.

CONTENTS

• Stack Overflows
• Shellcode
• Introduction to Format String Bugs
• Windows Shellcode
• Windows Overflows
• Overcoming Filters
• Introduction to Solaris Exploitation
• OS X Shellcode
• Cisco IOS Exploitation
• Protection Mechanisms
• Establishing a Working Environment
• Fault Injection
• The Art of Fuzzing
• Beyond Recognition: A Real Vulnerability versus a Bug
• Instrumented Investigation: A Manual Approach
• Tracing for Vulnerabilities
• Binary Auditing: Hacking Closed Source Software
• Alternative Payload Strategies
• Writing Exploits that Work in the Wild
• Attacking Database Software
• Unix Kernel Overflows
• Exploiting Unix Kernel Vulnerabilities
• Hacking the Windows Kernel

Download The ShellCoder's HandBook.

5. THE HACKER'S HANDBOOK WEB APPLICATION SECURITY FLAWS

This handbook is about finding and exploiting the web applications.

Authors: Dafydd Stuttard, Marcus Pinto.

CONTENTS

• Chapter 1 Web Application (In)security
• Chapter 2 Core Defense Mechanisms
• Chapter 3 Web Application Technologies
• Chapter 4 Mapping the Application
• Chapter 5 Bypassing Client-Side Controls
• Chapter 6 Attacking Authentication
• Chapter 7 Attacking Session Management
• Chapter 8 Attacking Access Controls
• Chapter 9 Attacking Data Stores
• Chapter 10 Attacking Back-End Components
• Chapter 11 Attacking Application Logic
• Chapter 12 Attacking Users: Cross-Site Scripting
• Chapter 13 Attacking Users: Other Techniques
• Chapter 14 Automating Customized Attacks
• Chapter 15 Exploiting Information Disclosure
• Chapter 16 Attacking Native Compiled Applications
• Chapter 17 Attacking Application Architecture
• Chapter 18 Attacking the Application Server
• Chapter 19 Finding Vulnerabilities in Source Code
• Chapter 20 A Web Application Hacker's Toolkit
• Chapter 21 A Web Application Hacker's Methodology

Download The Hacker's Handbook Web Application Security Flaws.

So, these are the top 5 best hacking books on the market. There may be more fascinating books in the future that make take place in the top list. But for now, these are the best hacking books. Read and share your experience with these books.

Related word

1. El Hacker
2. Growth Hacking Definicion
3. Google Hacking
4. Hacking Y Forensic Desarrolle Sus Propias Herramientas En Python Pdf
5. Growth Hacking Ejemplos
6. Libro Hacking Etico
7. Curso Growth Hacking
8. Hacking Tools
9. Growth Hacking Madrid
10. Hardware Hacking Tools
11. Drupal Hacking
12. Hacking 2018
13. Escuela Travel Hacking
14. Hacking Desde Cero
15. Rfid Hacking