Ranzy Locker Ransomware
First seen in early October, Ranzy Locker is a new RaaS tool from the creators of Ako. As such, it shares many of the same features of Ako, but uses a different file extraction routine as well as a new data leak site to aid in double-extortion attempts.
Summary
First seen in early October, Ranzy Locker is a new RaaS tool from the creators of Ako. As such, it shares many of the same features of Ako, but uses a different file extraction routine as well as a new data leak site to aid in double-extortion attempts.
Affected platforms
The following platforms are known to be affected:
Threat details
Introduction
Ranzy Locker is a newly observed ransomware-as-a-service (RaaS) tool that is believed to be the successor to the older Ako ransomware.
Previously called ThunderX, it is believed Ranzy Locker's creators updated and rebranded to avoid any association with ThunderX
Delivery
Activities
Once present on a target system, Ranzy Locker will search a list of hard-coded directories and extract any files contained within them. It then creates an archive of the extracted files and sends it to a command and control server. If successful, it will use the IcmpSendEcho function to ping scan the local network and identify any connected systems. Systems that respond will be checked for any network shares that Ranzy Locker can encrypt.
Files are encrypted using AES, with the key then further encrypted with RSA. Encrypted files are appended with the extension .ranzy.
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: 26 November 2020 11:53 am