MegaLocker Ransomware

MegaLocker (also known as NamPoHyu) is a newly observed ransomware tool.

Threat ID:: CC-3028
Category:: Ransomware
Threat Severity:: Low
Threat Vector:: Insecure network
Published:: 17 April 2019 12:00 AM

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

Summary

MegaLocker (also known as NamPoHyu) is a newly observed ransomware tool.

Threat details

At the time of publication, MegaLocker is delivered directly to target systems by the group operating it. They first scan the internet for devices with open ports before deploying several exploits to gain access. They will then attempt to laterally traverse the network these devices are connected in order to identify any network-attached storage devices or Samba instances

Once identified, the group will attempt to gain access to these using brute-force attacks before deploying MegaLocker to encrypt all available files.

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. Update 09 May 2019 A free decryptor for MegaLocker is available online. Users and organisations should be aware that NHS Digital do not test or validate recovery tools and that they use them at their own risk.

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.

Update 09 May 2019

A free decryptor for MegaLocker is available online. Users and organisations should be aware that NHS Digital do not test or validate recovery tools and that they use them at their own risk.

Last edited: 14 February 2020 2:48 pm