There is a new ransomware threat that businesses should be aware of, but PetrWrap ransomware is not exactly anything new. It is actually a form of ransomware that was first discovered in May last year. PetrWarp ransomware is, to all intents and purposes, almost exactly the same as the third incarnation of Petya ransomware. There is one key difference though. PetrWrap ransomware has been hijacked by a criminal gang and its decryption keys have been changed.
The criminal organization behind PetrWrap ransomware have taken Petya ransomware, for which there is no free decryptor, and have exploited a vulnerability that has allowed them to steal it and use it for their own gain. The attackers have simply added an additional module to the ransomware that modifies it on the fly. After all, why bother going to all the trouble of developing your own ransomware variant when a perfectly good one already exists!
Petya ransomware is being offered to spammers and scammers under an affiliate model. The ransomware authors are loaning the ransomware to others and take a percentage of the profits gained from ransoms that are paid. This is a common tactic to increase overall profits, just as retailers pay affiliate marketers to sell their products for a commission. In the case of ransomware-as-a-service, this allows the authors to infect more computers by letting others do the hard work of infecting computers.
Yet the gang behind PetrWrap has chosen not to give up a percentage of the profits. They are keeping all of the ransom payments for themselves. The module modifies and repurposes the malware code meaning even the Petya ransomware authors are unable to decrypt PetrWrap ransomware infections.
Kaspersky Lab research Anton Ivenov says “We are now seeing that threat actors are starting to devour each other and from our perspective, this is a sign of growing competition between ransomware gangs.” He pointed out the significance of this, saying “the more time criminal actors spend on fighting and fooling each other, the less organized they will be, and the less effective their malicious campaigns will be.”
Petya – and PetrWrap ransomware – is not a typical ransomware variant in that no files are encrypted. While Locky, CryptXXX, and Samsa search for a wide range of file types and encrypt them to prevent users from accessing their data, Petya uses a different approach. Petya modifies the master boot record that launches the operating system. The ransomware then encrypts the master file table. This prevents an infected computer from being able to locate files stored on the hard drive and stops the operating system from running. Essentially, the entire computer is taken out of action. The effect however is the same. Users are prevented from accessing their data unless a ransom is paid. Petya and PetrWrap ransomware can spread laterally and infect all endpoint computers and servers on the network. Rapid detection of an infection is therefore critical to limit the harm caused.
