Yatron Ransomware-as-a-Service

Yatron is a newly observed ransomware-as-a-service tool based on the well-known HiddenTear ransomware family.

Threat ID:: CC-2973
Category:: Ransomware
Threat Severity:: Medium
Threat Vector:: Email spam, Exploit
Published:: 14 March 2019 12:00 AM

Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

Yatron is a newly observed ransomware-as-a-service tool based on the well-known HiddenTear ransomware family.

Affected platforms

The following platforms are known to be affected:

Microsoft Windows

Microsoft Windows - All versions

Threat details

At the time of publication, Yatron is being distributed primarily via spam campaigns. However, once an initial device is affected Yatron has several methods for further propagation. It will copy itself to all removable drives, as well as folders used by several popular peer-to-peer (P2P) applications. Yatron will also attempt to propagate to other devices on the network using EternalBlue and DoublePulsar exploits; however, the code used to do this appears to be incomplete.

Once delivered, Yatron will attempt to bypass User Access Controls before encrypting all non-system files using an unknown algorithm. It will then display a dialogue window demanding payment, claiming the files will be deleted if the ransom is not paid within 72 hours.

Remediation steps

Type	Step
	Yatron's ransom note is displayed from a running process. Users can terminate this process to prevent deletion of encrypted files. 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.

Type

Step

Yatron's ransom note is displayed from a running process. Users can terminate this process to prevent deletion of encrypted files.

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.

Last edited: 14 February 2020 2:47 pm