(YARA) Detect XOR Encoded Malicious Patterns

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rule XOR_hunt
{
  meta:
    author = "Thomas Roccia | @fr0gger_"
    description = "100DaysOfYara - An attempt to catch malicious/suspicious pe file using xor for some data"
    status = "experimental"

  strings:
    $s1 = "http://" xor
    $s2 = "https://" xor
    $s3 = "ftp://" xor
    $s4 = "This program cannot be run in DOS mode" xor
    $s5 = "Mozilla/5.0" xor
    $s6 = "cmd /c" xor
    $s7 = "-ep bypass" xor

  condition:
     uint16(0) == 0x5A4D and any of them
}

Associated Techniques

Technique Name Technique ID's Categories Snippet(s)
XOR Operation U0701 E1027.m02

Matching Samples 10 most recent

Sample Name Matching Techniques First Seen Last Seen
RealFlight.exe 3 2026-10-07 1 week ago
RealFlight64.exe 1 2026-10-07 1 week ago
setup.exe 12 2026-10-04 1 week, 3 days ago
cc.dll 3 2026-10-02 1 week, 6 days ago
chatgpt.exe 8 2026-10-02 1 week, 6 days ago
5.exe 3 2026-09-30 2 weeks ago
new.exe 8 2026-09-29 2 weeks, 1 day ago
7z2603-x64.exe 3 2026-09-29 2 weeks, 1 day ago
XWormClient.exe 4 2026-09-28 2 weeks, 2 days ago
L2Oldies.dll 1 2026-09-23 3 weeks ago
View All

Created

January 4, 2024

Last Revised

March 27, 2026