Category: cryptocurrency

Jun 13 2018

Threat Report: Don’t Join Blockchain Revolution Without Ensuring Security

On May 19 researchers discovered a series of vulnerabilities in the blockchain-based EOS platform that can lead to remote control over participating nodes. Just four days prior, a mining pool server for the IOT platform HDAC was compromised, impacting the vast majority of miners. In January the largest-ever theft of cryptocurrencies occurred against the exchange Coincheck, resulting in the loss of US$532 million in NEM coin. Due to its increased popularity and profitability cybercriminals have been targeting all things blockchain. McAfee Advanced Threat Research team analysts have now published the McAfee Blockchain Threat Report to explain current threats against the users and implementers of blockchain technologies.

What is Blockchain?

Even if you have not heard of blockchain, you have likely heard of cryptocurrencies, namely Bitcoin, the most popular implementation. In late 2017 Bitcoin reached a value of $20,000 per coin, prompting a lot of interest in the currency—including from cybercriminals. Cryptocurrencies are built on top of blockchain, which records transactions in a decentralized way and enables a trusted “ledger” between trustless participants. Each block in the ledger is linked to the next block, creating a chain. Hence, the system is called a blockchain. The chain enables anyone to validate all transactions without going to an outside source. From this, decentralized currencies such as Bitcoin are possible.

Proof-of-work blockchain. Source: https://bitcoin.org/bitcoin.pdf.

Blockchain Attacks

Attackers have adopted many methods targeting consumers and businesses. The primary attack vectors include phishing, malware, implementation vulnerabilities, and technology. In a phishing scheme in January, Iota cryptocurrency lost $4 million to scams that lasted several months. Malware authors often change their focus. In late 2017 to early 2018 some have migrated from deploying ransomware to cryptomining. They have been found using open-source code such as XMRig for system-based mining and the mining service Coinhive.

Source: McAfee Labs

Implementation vulnerabilities are the flaws introduced when new technologies and tools are built on top of blockchain. The recent EOS attack is one example. In mid-July 2017 Iota suffered an attack that essentially enabled attackers to steal from any wallet. Another currency, Verge, was found with numerous vulnerabilities. Attackers exploiting the vulnerabilities were able to generate coins without spending any mining power.

Known attacks against the core blockchain technology are much more difficult to implement, although they are not unheard of. The most widely known attack is the 51% attack, or majority attack, which enables attackers to create their own chains at will. The group 51 Crew targeted small coins, including Krypton, and held them for ransom. Another attack, known as a Sybil attack, can allow an attacker to completely control a targeted victim’s ledger. Attempts have been made for larger scale Sybil attacks such as one in 2016. 

Dictionary Attacks

Blockchain may be a relatively new technology but that does not mean that old attacks cannot work. Mostly due to insecure user behavior, dictionary attacks can leverage some implementations of blockchain. Brain wallets, or wallets based on weak passwords, are insecure, yet people still use them. These wallets are routinely stolen, as was the case with the nearly BTC60 stolen from the following wallet:

This wallet recorded two transactions as recently as March 5, 2018. One incoming and one outgoing transaction occurred within roughly 15 minutes. Source: https://blockchain.info.

Exchanges Under Attack

The biggest players, and targets, in blockchain are cryptocurrency exchanges. Cryptocurrency exchanges can be thought of as banks in which you users create accounts, manage finances, and even trade currencies including traditional ones. One of the most notable incidents is the attack against Mt. Gox between 2011‒2014 that resulted in $450 million of Bitcoin stolen and led to the liquidation and closure of the company. Coincheck, previously mentioned, survived the attack and began reimbursing victims for their losses in March 2018. Not all recent exchanges fared so well. Bitcurex abruptly closed and led to an official investigation into the circumstances; Youbit suffered two attacks, leading the company into bankruptcy.

An advertisement for the shuttered Polish exchange Bitcurex.

Conclusion 

Blockchain technologies and its users are heavily targeted by profit-driven cybercriminals. Current attackers are changing their tactics and new groups are entering the space. As more businesses look to blockchain to solve their business problems and consumers increasingly rely on these technologies, we must be diligent in understanding where the threats lie to achieve proper and tailored risk management. New implementations must place security at the forefront. Cybercriminals have already enjoyed successes against the users and implementations of blockchain so we must prepare accordingly.

The post Threat Report: Don’t Join Blockchain Revolution Without Ensuring Security appeared first on McAfee Blogs.

Apr 28 2018

Darknet 2018-04-28 14:31:03

MyEtherWallet DNS Hack Causes 17 Million USD User Loss

Big news in the crypto scene this week was that the MyEtherWallet DNS Hack that occured managed to collect about $17 Million USD worth of Ethereum in just a few hours.

The hack itself could have been MUCH bigger as it actually involved compromising 1300 Amazon AWS Route 53 DNS IP addresses, fortunately though only MEW was targetted resulting in the damage being contained in the cryptosphere (as far as we know anyway).

Read the rest of MyEtherWallet DNS Hack Causes 17 Million USD User Loss now! Only available at Darknet.

Apr 11 2018

Parasitic Coin Mining Creates Wealth, Destroys Systems

The increasing popularity of cryptocurrencies has inspired some people to pursue coin mining, essentially making money online. (Mining is the processing of transactions in the digital currency system, in which new transactions are recorded in a digital ledger called the blockchain. Miners help to update the ledger to verify and collect new transactions to be added to the blockchain. In return, miners earn Bitcoins, for example.) Mining is resource intensive and legal if it is done with the proper permissions.

McAfee Labs has recently seen a huge increase in a malware variant, commonly known as CoinMiner or CoinMiner-FOZU!, which takes control of a victim’s computer to mine new coins by infecting user executables, injecting Coinhive JavaScript into HTML files, and blocking the domains of security products to stop signature updates.

CoinMiner-FOZU!, which we analyzed, has led all major coin-miner malware in prevalence in 2018. (March figures are incomplete.) Source: McAfee Labs.

The following graphs show statistics and geographic data for recent CoinMiner-FOZU! detections:

W32/CoinMiner employs—without a user’s consent—machine resources to mine coins for virtual currencies. Its parasitic nature makes it rare as well as destructive: The malware does not put a unique marker on each file it infects. Thus subsequent infections by the same malware will reinfect the victim’s files.

Analysis

After launching, CoinMiner copies itself into two hardcoded locations:

  • %Windows%\360\360Safe\deepscan\ZhuDongFangYu.exe
  • %filesystemroot%:\RECYCLER\S-5-4-62-7581032776-5377505530-562822366-6588\ZhuDongFangYu.exe

These two files are hidden and read only:

The binary executes from the first location and starts the parasitic infection process. The malware prepends itself to user-executable files but, unlike traditional file infectors, it does not allow the original file to run. It targets files with extensions .exe, .com, .scr, and .pif. This malware does not check for multiple infections. If the threat is deleted and later reinfects the system, the same files will again be targeted.

To prevent victims from restoring clean copies of their files, the malware deletes both ISO (disk image) and GHO (Norton Ghost) files:

 

Once CoinMiner finishes infecting other executable files, it injects a Coinhive script into HTML files. The Coinhive service provides cryptocurrency mining software, which using JavaScript code can be embedded in websites and use the site visitor’s processing power to mine the cryptocurrency:

CoinMiner disables the user account control feature, which notifies the user when applications make changes to the system. Through registry updates, it also disables folder options and registry tools, and deletes safe mode.

From its second location on an infected system—the hidden autorun.inf at the file system root—the malware ensures that it starts after rebooting:

To avoid detection by security products, CoinMiner puts security software domains in the hosts file and redirects them to 127.0.0.1, the loopback address on the victim’s system. If users have not created a local website, they will see an error page in their browsers. By doing this, the malware ensures that no victim can receive an update from the security vendor.

When the victim runs the script-injected HTML files, the Coinhive script executes, downloading coinhive.min.js (hash: 4d6af0dba75bedf4d8822a776a331b2b1591477c6df18698ad5b8628e0880382) from coinhive.com. This script takes over 100% of the CPU for mining using the function setThrottle(0). The mining stops when the victim closes the infected HTML file:

The simple hosts-file injection, hiding in the recycle bin, and maximizing CPU usage suggest that this malware has been written by a novice author. McAfee advises all users to keep their antimalware products up to date.

McAfee Detections

  • W32/CoinMiner
  • CoinMiner-FOZU![Partial hash]
  • TXT/CoinMiner.m
  • HTML/CoinMiner.m
  • JS/Miner.c

Hashes (SHA-256)

  • 80568db643de5f429e9ad5e2005529bc01c4d7da06751e343c05fa51f537560d
  • bb987f37666b6e8ebf43e443fc4bacd5f0ab795194f20c01fcd10cb582da1c57
  • 4d6af0dba75bedf4d8822a776a331b2b1591477c6df18698ad5b8628e0880382

The post Parasitic Coin Mining Creates Wealth, Destroys Systems appeared first on McAfee Blogs.

Apr 03 2018

Google bans cryptomining Chrome extensions because they refuse to play by the rules

Enlarge / Mining: no longer welcome in Chrome. (credit: Jeremy Buckingham / Flickr)

After a policy that previously permitted them, Google has decided to remove any and all Chrome extensions that mine for cryptocurrencies after finding that too many developers didn't play by the company's rules.

Google allowed Chrome extensions that performed mining with the proviso that the extensions clearly disclosed that they performed mining and performed no activity but mining. About 10 percent of extensions that mined within the browser followed these rules, but some 90 percent didn't. Instead, they mined surreptitiously, driving up people's electricity bills and running down their batteries without any informed consent on the user's behalf.

In response to this continued misbehavior, Google has decided to ban any and all cryptomining extensions. Effective immediately, the Chrome Web Store will no longer accept any extensions that mine for cryptocurrencies and, starting in June, will remove any existing extensions that mine.

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