Abyss Locker Ransomware Attacks Microsoft Windows and Linux Users

FortiGuard Labs has released a report detailing the emergence and impact of the Abyss Locker ransomware, which has been targeting Microsoft Windows and Linux platforms.

Abyss Locker, believed to be based on the HelloKitty ransomware source code, has been stealing and encrypting victims’ files, demanding ransom for file decryption, and preventing the release of stolen data.

The severity level of this ransomware is classified as high. The first Abyss Locker sample was detected in July 2023, but the ransomware’s origins may date even further.

The Windows version of Abyss Locker was discovered in January 2024, with a second version shortly after. The Linux variant, which targets VMware ESXi systems, has also been identified.

You can analyze a malware file, network, module, and registry activity with the ANY.RUN malware sandbox, and the Threat Intelligence Lookup that will let you interact with the OS directly from the browser.

Attack Method

The Windows version of Abyss Locker performs several actions to ensure the successful encryption of files. It deletes Volume Shadow Copies and system backups using commands like vssadmin.exe delete shadows /all /quiet and wmic SHADOWCOPY DELETE.

It also sets the boot status policy to disable automatic repair and ignore all boot failures.

The ransomware encrypts files and changes the file extension to “.abyss” or a random five-letter extension for the version 1 variant.

A ransom note titled “WhatHappened.txt” is dropped, and the desktop wallpaper is replaced with a message demanding a ransom.

The Linux version of Abyss Locker uses the esxcli command-line tool to manage VMware ESXi systems. It attempts to gracefully shut down running VMs before encrypting files with a “.crypt” extension.

A ransom note with the “.README_TO_RESTORE” extension is created for each encrypted file.

Both versions of the ransomware avoid encrypting specific file extensions and directories to maintain the system’s operability and ensure the victim can communicate with the attackers for ransom negotiation, reads Fortinet report.

Infection Vector

The infection vector for Abyss Locker is not specified, but it is likely similar to other ransomware groups.

The ransomware samples have been submitted from various regions, indicating a widespread attack.

While no current data leak site exposes victims’ names, a ransom negotiation site on TOR is available. The ransom demands vary, with higher amounts typically set for consumers.

The Abyss Locker ransomware poses a significant threat to Windows and Linux users, particularly those utilizing VMware ESXi systems.

IOCs

Abyss Locker Ransomware File IOCs

SHA2	Note
72310e31280b7e90ebc9a32cb33674060a3587663c0334daef76c2ae2cc2a462	Abyss Locker v2 (Linux)
3fd080ef4cc5fbf8bf0e8736af00af973d5e41c105b4cd69522a0a3c34c96b6d	Abyss Locker v2 (Windows)
9243bdcbe30fbd430a841a623e9e1bcc894e4fdc136d46e702a94dad4b10dfdc	Abyss Locker v1 (Windows)
0763e887924f6c7afad58e7675ecfe34ab615f4bd8f569759b1c33f0b6d08c64	Abyss Locker v1 (Windows)
dee2af08e1f5bb89e7bad79fae5c39c71ff089083d65da1c03c7a4c051fabae0	Abyss Locker v1 (Windows)
e6537d30d66727c5a306dc291f02ceb9d2b48bffe89dd5eff7aa2d22e28b6d7c	Abyss Locker v1 (Windows)
1d04d9a8eeed0e1371afed06dcc7300c7b8ca341fe2d4d777191a26dabac3596	Abyss Locker v1 (Windows)
1a31b8e23ccc7933c442d88523210c89cebd2c199d9ebb88b3d16eacbefe4120	Abyss Locker v1 (Windows)
25ce2fec4cd164a93dee5d00ab547ebe47a4b713cced567ab9aca4a7080afcb7	Abyss Locker v1 (Windows)
b524773160f3cb3bfb96e7704ef31a986a179395d40a578edce8257862cafe5f	Abyss Locker v1 (Windows)
362a16c5e86f13700bdf2d58f6c0ab26e289b6a5c10ad2769f3412ec0b2da711	Abyss Locker v1 (Windows)
e5417c7a24aa6f952170e9dfcfdf044c2a7259a03a7683c3ddb72512ad0cd5c7	Abyss Locker v1 (Windows)
056220ff4204783d8cc8e596b3fc463a2e6b130db08ec923f17c9a78aa2032da	Abyss Locker v1 (Windows)
877c8a1c391e21727b2cdb2f87c7b0b37fb7be1d8dd2d941f5c20b30eb65ee97	Abyss Locker v1 (Windows)
2e42b9ded573e97c095e45dad0bdd2a2d6a0a99e4f7242695054217e2bba6829	Abyss Locker v1 (Windows)

You can block malware, including Trojans, ransomware, spyware, rootkits, worms, and zero-day exploits, with Perimeter81 malware protection. All are extremely harmful, can wreak havoc, and damage your network.

Stay updated on Cybersecurity news, Whitepapers, and Infographics. Follow us on LinkedIn & Twitter.