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VHD Ransomware

VHD is a new ransomware tool created by the North Korean attributed Hidden Cobra APT group for their own use. As with a number of other Hidden Cobra malware, VHD appears to have been created solely to provide the group with access to cryptocurrency.

Threat ID:
CC-3583
Category:
Ransomware
Threat Severity:
Low
Threat Vector:
Hacking tool
Published:
30 July 2020 12:00 AM
Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

VHD is a new ransomware tool created by the North Korean attributed Hidden Cobra APT group for their own use. As with a number of other Hidden Cobra malware, VHD appears to have been created solely to provide the group with access to cryptocurrency.

Threat details

Introduction

First observed in March 2020, VHD is a ransomware tool believed to have been created but the Hidden Cobra advanced persistent threat group for use in their own campaigns.

Delivery

VHD is primarily distributed by Hidden Cobra's Dacls remote access trojan, but has also been observed in a small number of cases being delivered by an unidentified SMB spreading tool.

Activities

Once installed, VHD will attempt to stop security, database, and recovery services before encrypting all local non-system files using the AES algorithm in electronic codebook mode.

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 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.

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.

Indicators of compromise

Network indicators

IP addresses

  • 23.227.199[.]69
  • 104.232.71[.]7
  • 172.93.184[.]62

Domains

  • mnmski.cafe24[.]com 
Host indicators

SHA1 hashes

  • 6D12547772B57A6DA2B25D2188451983
  • D0806C9D8BCEA0BD47D80FA004744D7D
  • DD00A8610BB84B54E99AE8099DB1FC20
  • CCC6026ACF7EADADA9ADACCAB70CA4D6
  • EFD4A87E7C5DCBB64B7313A13B4B1012

Last edited: 30 July 2020 5:00 pm