Ransomware Research

CryptXXX Ransomware

CryptXXX is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on April 1, 2016, this ransomware has been actively targeting systems worldwide. Security researchers also track this malware under the aliases: CryptXXX 2.0.

Quick Facts

Ransomware Family
CryptXXX
First Seen
April 1, 2016
Known Aliases
CryptXXX 2.0

How CryptXXX Ransomware Works

Targeted Files

https://hummingbird.tistory.com/6410 https://app.any.run/tasks/1d8d1d05-07f4-4aef-812a-63675109f991/ https://www.sentinelone.com/blog/sophisticated-new-packer-identified-in-cryptxxx-ransomware-sample/ https://www.fortinet.com/blog/threat-research/cryptxxx-ransomware-emerges-for-a-slice-of-the-pie e40f89a16e44a65b53864fdfaa9dd70fc08382dcb2f3941d986056d2c50923ac -> XMS1, XMS2 export d88e1d4e38015ba121182b8d3288dd6b1e5deaf66430633d96802992414b856d -> MS1, MS2 export c87a3e7901defac48f531367d45306b7b2df33752b4a37f3744e029898bd1c1c -> MXS2 22fa2fc686d503d2ecef115f71e01bbae0f4a66e3c1550c39772065961037a16 -> AccessToken

File Encryption Patterns

CryptXXX modifies encrypted files using specific patterns to mark them as encrypted:

File extensions added after encryption:

..crypt..crypz..cryp1

Ransom Note and Payment Demands

After encrypting files, CryptXXX displays ransom notes demanding payment for file recovery:

file!README.HTML

Ransom message:

notes/!README.HTML

Note locations:

EveryFolder
filede_crypt_readme.txt

Ransom message:

notes/de_crypt_readme.txt

Note locations:

EveryFolder
filedecrypt-instructions.txt

Ransom message:

notes/decrypt-instructions.txt

Note locations:

EveryFolder
filedecrypt-instructions.html

Ransom message:

notes/decrypt-instructions.html

Note locations:

EveryFolder
filedecrypt-instructions.bmp

Ransom message:

notes/decrypt-instructions.bmp

Note locations:

EveryFolder
file/^@[A-F0-9]{12}\.html$/

Ransom message:

notes/@52CE675AD85E.html

Note locations:

EveryFolder
file/^@[A-F0-9]{12}\.txt$/

Ransom message:

notes/@52CE675AD85E.txt

Note locations:

EveryFolder
file/^![A-F0-9]{12}\.html$/

Ransom message:

notes/!4B3A1BD0EC11.html

Note locations:

EveryFolder
file/^![A-F0-9]{12}\.txt$/

Ransom message:

notes/!4B3A1BD0EC11.txt

Note locations:

EveryFolder

Technical Indicators

Associated Executable Files

The following executable files are associated with CryptXXX ransomware:

  • layouts.exe
  • adc0.tmp.dll
  • 3363.tmp.dll
  • rad30AF9.tmp.dll
  • rad24cd3.tmp.dll
  • rad5E0FA.tmp.dll

Elastio Can Help You

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About This Analysis

This CryptXXX ransomware analysis is part of Elastio's comprehensive ransomware detection database. Elastio provides advanced ransomware protection and recovery solutions, helping organizations defend against and recover from ransomware attacks like CryptXXX.

Last updated: July 30, 2025