Sarbloh Ransomware
Sarbloh ransomware, which is based on another open-source ransomware, is being used for political reasons and does not ask for payment.
Summary
Sarbloh ransomware, which is based on another open-source ransomware, is being used for political reasons and does not ask for payment.
Affected platforms
The following platforms are known to be affected:
Threat details
Introduction
Sarbloh is a newly observed ransomware that is distributed through malicious Word documents, which prompt users to enable macros. The ransomware will append ‘.sarbloh’ to every file’s name as part of the encryption process. The ransom demand states that the files will not be recoverable until the demands of the farmers have been met.
Delivery
Sarbloh is distributed through Word documents in phishing email campaigns. Once the document is opened, a prompt will appear, asking users to enable macros to view it correctly. The document contains macros with heavily obfuscated VBA code, which when opened, calls Background Intelligent Transfer Service to download the payload.
Activities
The ransomware will enumerate the file system and encrypt all files that match a hardcoded extension list. Any encrypted files have ‘.sarbloh’ added to the end. It then drops a ransom note, which states that the user’s files are encrypted “using military grade encryption” and will not be recoverable until Sarbloh's creators' political demands are met. Sarbloh is based on open-source KhalsaCrypt ransomware.
Remediation advice
If a device on your network becomes infected with ransomware it will begin encrypting files, which may also include remote files on network locations. The only guaranteed way to recover from a ransomware infection is to restore all affected files from their most recent backup. To limit the impact of a ransomware infection, NHS Digital advises that:
- Critical data is frequently saved in multiple backup locations.
- At least one backup is kept offline at any time (separated from live systems).
- Backups and incident recovery plans are tested to ensure that data can be restored when needed.
- User account permissions for modifying data are regularly reviewed and restricted to the minimum necessary.
- Infected systems are disconnected from the network and powered down as soon as practicable.
- Any user account credentials that may have been compromised should be reset on a clean device
- Where infected systems cannot be quarantined with confidence, then an affected organisation should disconnect from national networks to limit propagation.
Additionally, to prevent and detect an infection, NHS Digital advises that:
- Secure configurations are applied to all devices.
- Security updates are applied at the earliest opportunity.
- Tamper protection settings in security products are enabled where available.
- Obsolete platforms are segregated from the rest of the network.
- IT usage policies are reinforced by regular training to ensure all users know not to open unsolicited links or attachments.
- Multi-factor authentication (MFA) and lockout policies are used where practicable, especially for administrative accounts.
- Administrative accounts are only used for necessary purposes.
- Remote administration services use strongly encrypted protocols and only accept connections from authorised users or locations.
- Systems are continuously monitored, and unusual activity is investigated, so that a compromise of the network can be detected as early as possible.
Please note that NCSC maintains guidance for securely configuring a wide range of end user device (EUD) platforms. For further details refer to their end user device security guidance pages.
Indicators of compromise
Last edited: 11 March 2021 12:05 pm