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Hermes Ransomware

First observed in 2017, Hermes is a ransomware tool sold to other threat actors for use in their own campaigns
Threat ID:
CC-2562
Category:
Ransomware
Threat Severity:
Medium
Threat Vector:
Email spam, Phishing
Published:
2 August 2018 12:00 AM
Report a cyber attack: call 0300 303 5222 or email [email protected]

This content has been archived

This article no longer conforms to NHS Digital's standards for cyber alerts, and may contain outdated or inaccurate information.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

First observed in 2017, Hermes is a ransomware tool sold to other threat actors for use in their own campaigns

Affected platforms

The following platforms are known to be affected:

Microsoft Windows

  • Microsoft Windows - All versions

Threat details

Hermes is distributed via spam and phishing campaigns using attached malicious documents or, through a number of exploit kits such as Sundown. Several of the documents use an Adobe Flash Player 0-day exploit (CVE-2018-4878) to compromise an affected device.

Once on a device, Hermes will check for Russian, Belarusian or Ukrainian language packs and will shutdown if any of these are detected. It will then use a User Account Control (UAC) bypass, known as Eleven, to elevate its privileges in order to launch a VBS file to delete all Shadow Volume Copies and other backup files. Hermes will then launch another file to scan all local or unmapped network drives and encrypt all files with a target extension using AES encryption. Encrypted files do not have a new extension appended to them.

For further information

Threat updates

Date Update
21 Aug 2018

Hermes version 2.1 has been advertised for sale online. It has the capability to resume encryption if the system is restarted. Hermes continues to exclude Russian, Ukrainian and Belarusian users.

Remediation steps

Type Step

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.

CVE Vulnerabilities

Status

CVE-2018-4878

Last edited: 17 February 2020 12:44 pm