BlackRuby Ransomware

BlackRuby is a newly observed ransomware tool that installs a cryptocurrency mining programme alongside the encryption routine.

Threat ID:: CC-2066
Category:: Ransomware
Threat Severity:: Medium
Threat Vector:: Exploit, Email spam
Published:: 22 February 2018 12:00 AM

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

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This article no longer conforms to NHS Digital's standards for cyber alerts, and may contain outdated or inaccurate information. Use of this information contained in this page is at your own risk

Summary

BlackRuby is a newly observed ransomware tool that installs a cryptocurrency mining programme alongside the encryption routine.

Affected platforms

The following platforms are known to be affected:

Microsoft Windows

Microsoft Windows - All versions

Threat details

At present it appears that BlackRuby is delivered via spam emails containing malicious documents, although there are unconfirmed instances of devices being compromised through Remote Desktop Protocol (RDP) brute-force attacks.

Once installed, BlackRuby uses the FreeGeoIP API to check if the compromised device has an Iranian IP address, terminating itself without performing any malicious activity if it does. If the device is non-Iranian then BlackRuby will extract and execute a Monero miner before running a series of commands to delete Volume Shadow Copies and disable Windows Error Recovery and Log Messages services. The mining programme will attempt to mine as fast as possible, consuming large amounts of CPU and memory resources and noticeably slowing down the affected device.

BlackRuby uses hybrid RSA and AES encryption, with files renamed with the format Encrypted_[scrambled_filename].BlackRuby, before dropping a ransom note in every directory. The mining programme will continue to run throughout the encryption process and will persist even if ransom payments are made.

Threat updates

Date	Update
10 Apr 2018	It has come to CareCERT's attention that BlackRuby is part of a larger ransomware family, known as InfiniteTear, along with Zenis and WhiteRose.

Remediation steps

Type	Step
	If a computer 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, antivirus 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 on the basis 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 infected machine and unplugging / 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 PC). 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. Additionally, if RDP is not used then ensure port 3389 (TCP/UDP) is blocked at your internet firewall. If RDP is used: Ensure only authorised users are granted RDP permissions. Ensure authorised users have a strong password. Protect RDP connections with multifactor authentication. Only allow RDP to run through VPN connections.

Type

Step

If a computer 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, antivirus 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 on the basis 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 infected machine and unplugging / 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 PC).

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.

Additionally, if RDP is not used then ensure port 3389 (TCP/UDP) is blocked at your internet firewall. If RDP is used:

Ensure only authorised users are granted RDP permissions.
Ensure authorised users have a strong password.
Protect RDP connections with multifactor authentication.
Only allow RDP to run through VPN connections.

Last edited: 17 February 2020 12:38 pm