Inside the Ragnar Locker ransomware

The Ragnar Locker ransomware gang has taken credit for a recent attack on the Greek pipeline company DEFSA, according to security researchers.

In a research paper on the gang and how its ransomware strain operates, Cybereason notes that DEFSA is the second important pipeline company that has been hit by ransomware in the past 15 months, after the Darkside group’s attack on Colonial Pipeline.

In addition, four energy companies were hit recently by ransomware, including three in Europe. Hive has claimed it hit China’s ENN Group, BlackCat says it hit Luxembourg’s Creos/Encevo, and Cl0p hit South Staffordshire PLC.

These attacks suggest an increasing focus on the energy sector.

The report notes that Ragnar Locker, which has been running since 2019, checks infected devices before executing and won’t run in Russia, Ukraine, or countries in the Commonwealth of Independent States, a group of nations formerly part of the Soviet Union.

Like many pieces of malware, Ragnar Locker checks if security products such as antivirus, virtual-based software, backup solutions, and IT remote management solutions are installed.

If the PC/server isn’t on the list of banned countries, the ransomware extracts information about the infected machine. First, it collects the computer name and the user name using the API calls GetComputerNameW and GetUserNameW.

Then the ransomware queries the registry to collect the machine GUID and Windows version.

Before encryption, Ragnar Locker spawns the following child processes:

• • wmic.exe shadowcopy delete: This system command deletes all shadow copies on the victim’s system, preventing data recovery by the victim
  • vssadmin delete shadows /all /quiet: This system command also deletes shadow copies, preventing data recovery by the victim
  • notepad.exe [User path]\RGNR_AABBCCDD.txt : This command launches Notepad.exe to show the ransom note to the victim.

After the ransom note is created, the actual file encryption process initiates using the Salsa20 algorithm. It excludes files ending in .db, .sys, .dll, lnk, .msi, .drv and .exe.

The report includes a list of indicators of compromise.

Earlier this year the FBI also released a report on this group.