Privacy Ninja



        • Secure your network against various threat points. VA starts at only S$1,000, while VAPT starts at S$4,000. With Price Beat Guarantee!

        • API Penetration Testing
        • Enhance your digital security posture with our approach that identifies and addresses vulnerabilities within your API framework, ensuring robust protection against cyber threats targeting your digital interfaces.

        • On-Prem & Cloud Network Penetration Testing
        • Boost your network’s resilience with our assessment that uncovers security gaps, so you can strengthen your defences against sophisticated cyber threats targeting your network

        • Web Penetration Testing
        • Fortify your web presence with our specialised web app penetration testing service, designed to uncover and address vulnerabilities, ensuring your website stands resilient against online threats

        • Mobile Penetration Testing
        • Strengthen your mobile ecosystem’s resilience with our in-depth penetration testing service. From applications to underlying systems, we meticulously probe for vulnerabilities

        • Cyber Hygiene Training
        • Empower your team with essential cybersecurity knowledge, covering the latest vulnerabilities, best practices, and proactive defence strategies

        • Thick Client Penetration Testing
        • Elevate your application’s security with our thorough thick client penetration testing service. From standalone desktop applications to complex client-server systems, we meticulously probe for vulnerabilities to fortify your software against potential cyber threats.

        • Source Code Review
        • Ensure the integrity and security of your codebase with our comprehensive service, meticulously analysing code quality, identifying vulnerabilities, and optimising performance for various types of applications, scripts, plugins, and more

        • Email Spoofing Prevention
        • Check if your organisation’s email is vulnerable to hackers and put a stop to it. Receive your free test today!

        • Email Phishing Excercise
        • Strengthen your defense against email threats via simulated attacks that test and educate your team on spotting malicious emails, reducing breach risks and boosting security.

        • Cyber Essentials Bundle
        • Equip your organisation with essential cyber protection through our packages, featuring quarterly breached accounts monitoring, email phishing campaigns, cyber hygiene training, and more. LAUNCHING SOON.

New RegretLocker Ransomware Targets Windows Virtual Machines

New RegretLocker Ransomware Targets Windows Virtual Machines

A new ransomware called RegretLocker uses a variety of advanced features that allows it to encrypt virtual hard drives and close open files for encryption.

RegretLocker was discovered in October and is a simple ransomware in terms of appearance as it does not contain a long-winded ransom note and uses email for communication rather than a Tor payment site.

RegretLocker ransom note
RegretLocker ransom note
Source: BleepingComputer

When encrypting files, it will append the innocuous-sounding .mouse extension to encrypted file names.

RegretLocker encrypted files
RegretLocker encrypted files
Source: BleepingComputer

What it lacks in appearance, though, it makes up for in advanced features that we do not usually see in ransomware infections, as described below.

Also Read: How To Prevent WhatsApp Hack: 7 Best Practices

RegretLocker mounts virtual hard disks

When creating a Windows Hyper-V virtual machine, a virtual hard disk is created and stored in a VHD or VHDX file.

These virtual hard disk files contain a raw disk image, including a drive’s partition table and partitions, and like regular disk drives, can range in size from a few gigabytes to terabytes.

When a ransomware encrypts files on a computer, it is not efficient to encrypt a large file as it slows down the entire encryption process’s speed.

In a sample of the ransomware discovered by MalwareHunterTeam and analyzed by Advanced Intel’s Vitali Kremez, RegretLocker uses an interesting technique of mounting a virtual disk file so each of its files can be encrypted individually.

To do this, RegretLocker uses the Windows Virtual Storage API OpenVirtualDiskAttachVirtualDisk, and GetVirtualDiskPhysicalPath functions to mount virtual disks.

Mounting a VHD file
Mounting a VHD file

As shown by a debug message in the ransomware, it is specifically searching for VHD and mounting them when detected.

parse_files() | Found virtual drive: %ws in path: %s

Once the virtual drive is mounted as a physical disk in Windows, the ransomware can encrypt each one individually, which increases the speed of encryption.

The code used by RegretLocker to mount a VHD is believed to have been taken from a recently published research by security researcher smelly__vx.

Also Read: 15 Best Tools For Your Windows 10 Privacy Settings Setup

In addition to using the Virtual Storage API, RegretLocker also utilizes the Windows Restart Manager API to terminate processes or Windows services that keep a file open during encryption.

When using this API, Kremez told BleepingComputer if the name of a process contains ‘vnc’, ‘ssh’, ‘mstsc’, ‘System’, or ‘svchost.exe’, the ransomware will not terminate it. This exception list is likely used to prevent the termination of critical programs or those used by the threat actor to access the compromised system.

Windows Restart Manager exception list
Windows Restart Manager exception list

The Windows Restart Manager feature is only used by a few ransomware such as REvil (Sodinokibi), Ryuk, ContiThunderX/AkoMedusa LockerSamSam, and LockerGoga.

RegretLocker is not very active at this point, but it is a new family that we need to keep an eye on.



Subscribe to our mailing list to get free tips on Data Protection and Data Privacy updates weekly!

Personal Data Protection


We have assisted numerous companies to prepare proper and accurate reports to PDPC to minimise financial penalties.


Click one of our contacts below to chat on WhatsApp

× Chat with us