Group-IB discovered that QakBot (aka Qbot) operators have abandoned ProLock for Egregor ransomware.

ProLock = Egregor

The analysis of attacks where Egregor has been deployed revealed that the TTPs used by the threat actors are almost identical to the ones used by the ProLock operators.

First, the initial access is always gained via QakBot delivered through malicious Microsoft Excel documents impersonating DocuSign-encrypted spreadsheets. Moreover, Egregor operators have been using Rclone for data exfiltration – same as with ProLock. Same tools and naming convention have been used as well, for example md.exe, rdp.bat, svchost.exe.

Egregor operators leverage the intimidation tactics, they threaten to release sensitive info on the leak site they operate instead of just encrypting compromised networks. The biggest ransom demand was at $4 million worth of BTC till now.

Egregor operators in a spam of 3 months have managed to successfully hit 69 companies around the world with 32 targets in the US, 7 victims in France and Italy each, 6 in Germany, and 4 in the UK. Other victims happened to be from the APAC, the Middle East, and Latin America. Egregor’s favorite sectors are Manufacturing (28.9% of victims) and Retail (14.5%).

Egregor ransomware sample obtained during a recent incident response engagement revealed that the executable code of Egregor is very similar to Sekhmet.

Egregor source code bears similarities with Maze ransomware as well. The decryption of the final payload is based on the command-line provided password.Egregor operators use the combination of ChaCha8 stream cipher and RSA-2048 for file encryption.

The use of CobaltStike and QakBot is to watch when hunting for Egregor. More threat hunting and detection tips from Group-IB DFIR team as well as a detailed technical analysis of Egregor operations are available in Group-IB’s blog.