Pierluigi Paganini December 17, 2021

Experts reported the resurgence of the Phorpiex botnet, in one year it allowed to steal crypto assets worth of half a million dollars.

Experts at Check Point Research have monitored the resurgence of the Phorpiex botnet, an old threat that was involved in sextortion spam campaigns, crypto-jacking, cryptocurrency clipping (substituting the original wallet address saved in the clipboard with the attacker’s wallet address during a transaction) and ransomware attacks in the past.

The new variant, dubbed “Twizt,” could operate without active C2 servers in peer-to-peer mode. Each of the infected computers can act as a server and send commands to other bots in a chain. Experts estimated that in one year it allowed to steal crypto assets worth of 500,000 dollars.

The botnet has been active since at least 2016, but in August the criminal organization behind the Phorpiex botnet have shut down their operations and put the source code of the bot for sale on a cybercrime forum in on a dark web.

From the announcement, the botnet was likely operated by two individuals, it it is unclear if the botnet was actually sold. Check Point experts noticed that less than two weeks later, the C&C servers were back online to distribute the new Twizt variant.

In 2021, Phorpiex infections were found in 96 countries, most of the victims are located in Ethiopia, Nigeria and India:

Phorpiex crypto-clipper supports more than 30 wallets for different blockchains.

“The Phorpiex crypto-clipper supports over 30 wallets for different blockchains, including Bitcoin, Ethereum, Dogecoin, Dash, Monero, and Zilliqa. We focused only on the most popular blockchains – Bitcoin and Ethereum. We managed to find 60 unique Bitcoin wallets and 37 Ethereum wallets used by the Phorpiex crypto-clipper. Many wallets have been active for several years.” reads the analysis published by CheckPoint. “In a one-year period between November 2020 to November 2021, Phorpiex bots hijacked 969 transactions and stole 3.64 Bitcoin, 55.87 Ether, and $55,000 in ERC20 tokens.”

Experts noticed that the total value of the stolen money could be even higher because they didn’t include other blockchains in their investigation. The average stolen value in hijacked transactions decreases when the cryptocurrency price rises. 

“Malware with the functionality of a worm or a virus can continue to spread autonomously for a long time without any further involvement by its creators. However, in most cases the creators need to use C&C servers to control the bots to be able to profit from the botnet. We should note that for a botnet on the scale of Phorpiex, it is quite difficult to find reliable hosting that does not block the C&C server.” concludes the analysis. “The creators are further disadvantaged if the IP addresses of the C&C servers are added to deny-lists, thereby reducing the efficiency of controlling the botnet. Changing the IP address of the C&C server can be very difficult. The Phorpiex botnet uses techniques that effectively achieve its goals without C&C servers.” concludes the analysis.”

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Pierluigi Paganini

(SecurityAffairs – hacking, Phorpiex botnet)

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