Threat Signal Report

Somnia Ransomware Targets Ukraine

description-logo Description

UPDATE 2022/11/16: Updated detection information for Somnia ransomware samples.


FortiGuard Labs is aware of a report that a new ransomware "Somnia" was observed in attacks against Ukraine. Somnia ransomware was deployed as a final payload in multiple staged attacks involving a fake IP scanner, Vidar stealer, and Cobalt Strike. The attack was attributed to FRwL (aka Z-Team, UAC-0118).


Why is this Significant?

This is significant because Somnia is the latest ransomware that reportedly targets Ukrainian interests. Other ransomware variants that previously targeted Ukraine include are but not restricted to Prestige, AcidRain, DoubleZero, CaddyWiper, IssacWiper, HermeticWiper, and WhisperGate.


How was Somnia Ransomware Distributed?

Somnia ransomware was reportedly distributed in an attack chain that goes through multiple stages. First, the attacker creates a fake Advanced IP Scanner Web site in an attempt to trick Ukrainian organizations into downloading and installing Vidar stealer disguised as "Advanced IP Scanner" installer.


Once a victim's machine is compromised by Vidar stealer, it tries to steal Telegram's session data, which is then used to compromise VPN connections giving the attacker access to the victim's network. Cobalt Strike was seen deployed to the compromised network. Reportedly Rсlone, Anydesk, and Ngrok were observed for data exfiltration. Finally, Somnia ransomware deployed to encrypt files on the compromised machines.


What is Somnia Ransomware?

Somnia is a ransomware that encrypts files on compromised machines. According to CERT-UA, there are two different types of Somnia ransomware; the one uses 3DES algorithm for file encryption and the other uses the AES algorithm. The affected files have a ".somnia" file extension.


Somnia ransomware targets and encrypts files with the following extensions:



File extensions targeted by Somnia ransomware (screenshot taken from a CERT-UA report)

Since Somnia ransomware does not drop any ransom note and attacker's contact information, victims will likely will not be able to decrypt the encrypted files.


What is the Status of Protection?
FortiGuard Labs detects Somnia ransomware with the following AV signatures:

  • MSIL/Somnia.C!tr.ransom
  • W32/Somnia.C!tr.ransom

FortiGuard Labs detects the fake Advanced IP Scanner used as initial infection vector with the following AV signature:

W32/PossibleThreat

Reported network IOCs are blocked by Webfiltering.

Definitions

Traffic Light Protocol

Color When Should it Be used? How may it be shared?

TLP: RED

Not for disclosure, restricted to participants only.
Sources may use TLP:RED when information cannot be effectively acted upon by additional parties, and could lead to impacts on a party's privacy, reputation, or operations if misused. Recipients may not share TLP:RED information with any parties outside of the specific exchange, meeting, or conversation in which it was originally disclosed. In the context of a meeting, for example, TLP:RED information is limited to those present at the meeting. In most circumstances, TLP:RED should be exchanged verbally or in person.

TLP: AMBER

Limited disclosure, restricted to participants’ organizations.
Sources may use TLP:AMBER when information requires support to be effectively acted upon, yet carries risks to privacy, reputation, or operations if shared outside of the organizations involved. Recipients may only share TLP:AMBER information with members of their own organization, and with clients or customers who need to know the information to protect themselves or prevent further harm. Sources are at liberty to specify additional intended limits of the sharing: these must be adhered to.

TLP: GREEN

Limited disclosure, restricted to the community.
Sources may use TLP:GREEN when information is useful for the awareness of all participating organizations as well as with peers within the broader community or sector. Recipients may share TLP:GREEN information with peers and partner organizations within their sector or community, but not via publicly accessible channels. Information in this category can be circulated widely within a particular community. TLP:GREEN information may not be released outside of the community.

TLP: WHITE

Disclosure is not limited.
Sources may use TLP:WHITE when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright rules, TLP:WHITE information may be distributed without restriction.