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Ragnarok Ransomware

Ragnarok is a newly observed ransomware tool that exploits the Citrix ADC and Gateway remote code execution vulnerability to propagate across vulnerable networks.

Threat ID:
CC-3354
Category:
Threat Severity:
Low
Threat Vector:
Published:
30 January 2020 12:00 AM
Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

Ragnarok is a newly observed ransomware tool that exploits the Citrix ADC and Gateway remote code execution vulnerability to propagate across vulnerable networks.

Threat details

At the time of publication, Ragnaork appears to be delivered manually. An unknown CVE-2019-19781 exploit is first deployed against identified vulnerable devices which, if successful, then downloads a small shell script. This script then searches for the python2 binary before downloading two additional files, one containing Ragnarok whilst the other contains a Meterpreter payload and the EternalBlue exploit, along with a scanner module. These files are then unpacked and executed.

Once installed, Ragnarok will attempt to encrypt all non-system files using an unknown algorithm before dropping a ransom note in each folder.

Remediation steps

Type Step

Citrix has addressed CVE-2019-19781 in all affected products. Organisations are encouraged to review the following Citrix security pages and apply any relevant updates:

If a device on your network becomes infected with ransomware it will begin encrypting local machine files and files on any network the logged-in user has permission to access. For system administration accounts this may include backup storage locations.

To avoid becoming infected with ransomware, ensure that:

  • A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails.
  • All operating systems, anti-virus and other security products are kept up to date.
  • All day to day computer activities such as email and internet are performed using non-administrative accounts and that permissions are always assigned based on the principle of least privilege.
  • Your organisation adopts a holistic all-round approach to Cyber Security as advocated by the 10 Steps to Cyber Security.

Identifying the source of infection:
Identifying the affected device and disconnecting or quarantining it from the network is essential to damage limitation.

  • Users should immediately report infections to their IT support provider, disconnect their network cable and power the computer down.
  • File auditing should be enabled, and file server logs should be monitored to detect signs of unauthorised encryption and allow the source of encryption to be identified (i.e. the infected device).

To limit the damage of ransomware and enable recovery:
All critical data must be backed up, and these backups must be sufficiently protected/kept out of reach of ransomware.

  • Multiple backups should be created including at least one off-network backup (e.g. to tape).
    The only guaranteed way to recover from a ransomware infection is to restore all affected files from their most recent backup.

Indicators of compromise

Main indicators

IP Addresses

  • 198[.]44[.]227[.]126
  • 45[.]120[.]53[.]214

Email Addresses

  • asgardmaster5@protonmail[.]com
  • j.jasonm@yandex[.]com
  • ragnar0k@ctemplar[.]com

Filenames

  • .new.zip
  • avpass.exe
  • de.py
  • eternalblue.replay
  • ld.sh
  • piz.Lan
  • scan.py
  • since1969.exe
  • x64.dll
  • x86.dll
  • xp_eternalblue.replay

MD5 File Hashes

  • 01af5ad23a282d0fd40597c1024307ca
  • 0caf9be8fd7ba5b605b7a7b315ef17a0
  • 48452dd2506831d0b340e45b08799623
  • 55b40e0068429fbbb16f2113d6842ed2
  • 6cf1857e569432fcfc8e506c8b0db635
  • 91dd06f49b09a2242d4085703599b7a7
  • 9aa67d856e584b4eefc4791d2634476a
  • 9e408d947ceba27259e2a9a5c71a75a8
  • b0acb27273563a5a2a5f71165606808c
  • bd977d9d2b68dd9b12a3878edd192319
  • e345c861058a18510e7c4bb616e3fd9f

CVE Vulnerabilities

CVE-2019-19781

Last edited: 10 January 2022 4:45 pm