YARA · Trellix Advanced Research Center
TRELLIX_ARC_RANSOM_Exorcist
Rule to detect Exorcist
- Author
- McAfee ATR Team
- Date
- 2020-09-01
- Modified
- 2020-10-12
- Score / Quality
- 75 / 70
What this rule detects
Rule to detect Exorcist
Associated malware family: Exorcist.
Targets: Windows PE.
It defines 2 patterns (0 text, 2 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
rule TRELLIX_ARC_RANSOM_Exorcist : RANSOMWARE FILE
{
meta:
= "Rule to detect Exorcist"
= "McAfee ATR Team"
= "38ab069d-b030-5459-a42f-7ecd5963e68f"
= "2020-09-01"
= "2020-10-12"
= "https://github.com/advanced-threat-research/Yara-Rules/"
= "https://github.com/advanced-threat-research/Yara-Rules//blob/1919562a59f190bda60c982424f6a24c542ee3e0/ransomware/RANSOM_Exorcist.yar#L1-L25"
= "https://github.com/advanced-threat-research/Yara-Rules//blob/1919562a59f190bda60c982424f6a24c542ee3e0/LICENSE"
= "793dcc731fa2c6f7406fd52c7ac43926ac23e39badce09677128cce0192e19b0"
= "c376382e60aae0f661151495097d3d93f185faebb11781dbf083324c23a07247"
= 75
= 70
= "RANSOMWARE, FILE"
= "v1"
= "ransomware"
= "Ransomware:W32/Exorcist"
= "Cybercrime"
= "Cybercrime"
= "Unknown"
strings:
$sq1 = { 48 8B C4 48 89 58 08 48 89 70 10 48 89 78 18 4C 89 60 20 55 41 56 41 57 48 8D 68 A1 48 81 EC 90 00 00 00 49 8B F1 49 8B F8 4C 8B FA 48 8B D9 E8 ?? ?? ?? ?? 45 33 E4 85 C0 0F 85 B1 00 00 00 48 8B D7 48 8B CB E8 9E 02 00 00 85 C0 0F 85 9E 00 00 00 33 D2 48 8B CB E8 ?? ?? ?? ?? 45 33 C0 48 8D 15 ?? ?? ?? ?? 48 8B CB E8 ?? ?? ?? ?? 45 8D 44 24 01 48 8B D7 48 8B C8 E8 ?? ?? ?? ?? 48 8B D0 48 8B CB 48 8B F8 FF 15 ?? ?? ?? ?? 4C 89 64 24 30 45 33 C9 C7 44 24 28 80 00 00 E8 45 33 C0 BA 00 00 00 C0 C7 44 24 20 03 00 00 00 48 8B CF FF 15 ?? ?? ?? ?? 4C 8B F0 48 8D 48 FF 48 83 F9 FD 77 25 48 8D 55 2F 48 8B C8 FF 15 ?? ?? ?? ?? 4C 39 65 2F 75 3B 49 8B CE FF 15 ?? ?? ?? ?? 48 8B CF FF 15 ?? ?? ?? ?? 48 8B CF E8 ?? ?? ?? ?? 4C 8D 9C 24 90 00 00 00 49 8B 5B 20 49 8B 73 28 49 8B 7B 30 4D 8B 63 38 49 8B E3 41 5F 41 5E 5D C3 48 8D 45 FB 4C 89 65 1F 4C 8D 4D FF 48 89 44 24 20 4C 8B C6 4C 89 65 07 48 8D 55 07 4C 89 65 FF 48 8D 4D 1F 44 89 65 FB E8 ?? ?? ?? ?? 45 33 C9 4C 8D 05 3C F5 FF FF 49 8B D7 49 8B CE FF 15 ?? ?? ?? ?? 48 8D 55 17 49 8B CE FF 15 ?? ?? ?? ?? 49 8B CE 44 89 65 F7 E8 ?? ?? ?? ?? 49 8B F4 4C 89 65 0F 4C 39 65 17 0F 8E 9D 00 00 00 C1 E0 10 44 8B F8 F0 FF 45 F7 B9 50 00 00 00 E8 ?? ?? ?? ?? 8B 4D 13 48 8B D8 89 48 14 89 70 10 4C 89 60 18 44 89 60 28 4C 89 70 30 48 8B 4D 07 48 89 48 48 48 8D 45 F7 B9 00 00 01 00 48 89 43 40 E8 ?? ?? ?? ?? 33 D2 48 89 43 20 41 B8 00 00 01 00 48 8B C8 E8 ?? ?? ?? ?? 48 8B 53 20 4C 8D 4B 38 41 B8 00 00 01 00 48 89 5C 24 20 49 8B CE FF 15 ?? ?? ?? ?? EB 08 33 C9 FF 15 ?? ?? ?? ?? 8B 45 F7 3D E8 03 00 00 77 EE 49 03 F7 48 89 75 0F 48 3B 75 17 0F 8C 6B FF FF FF EB 03 8B 45 F7 85 C0 74 0E 33 C9 FF 15 ?? ?? ?? ?? 44 39 65 F7 77 F2 48 8B 4D 07 E8 ?? ?? ?? ?? 48 8B 4D 1F 33 D2 E8 ?? ?? ?? ?? 49 8B CE FF 15 ?? ?? ?? ?? 4C 89 64 24 30 45 33 C9 C7 44 24 28 80 00 00 00 45 33 C0 BA 00 00 00 C0 C7 44 24 20 03 00 00 00 48 8B CF FF 15 ?? ?? ?? ?? 48 8B D8 48 8D 48 FF 48 83 F9 FD 77 51 48 8D 55 37 48 8B C8 FF 15 ?? ?? ?? ?? 48 8B 55 37 45 33 C9 45 33 C0 48 8B CB FF 15 ?? ?? ?? ?? 44 8B 45 FB 4C 8D 4D 27 48 8B 55 FF 48 8B CB 4C 89 64 24 20 FF 15 ?? ?? ?? ?? 48 8B 4D FF E8 ?? ?? ?? ?? 48 8B CB FF 15 ?? ?? ?? ?? E9 14 FE FF FF 48 8B CF E8 ?? ?? ?? ?? 48 8B 4D FF E9 06 FE FF FF }
$sq2 = { 48 8B C4 48 81 EC 38 01 00 00 48 8D 50 08 C7 40 08 04 01 00 00 48 8D 4C 24 20 FF 15 ?? ?? ?? ?? 48 8D 4C 24 20 E8 ?? ?? ?? ?? 48 81 C4 38 01 00 00 C3 }
condition:
uint16( 0 ) == 0x5a4d and any of them
}
Strings (2 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $sq1 | hex | { 48 8B C4 48 89 58 08 48 89 70 10 48 89 78 18 4C 89 60 20 55 41 56 41 57 48 8D 68 A1 48 81 EC 90 00 00 00 49 8B F1 49 8B F8 4C 8B FA 48 8B D9 E8 ?? ?? ?? ?? 45 … | |
| $sq2 | hex | { 48 8B C4 48 81 EC 38 01 00 00 48 8D 50 08 C7 40 08 04 01 00 00 48 8D 4C 24 20 FF 15 ?? ?? ?? ?? 48 8D 4C 24 20 E8 ?? ?? ?? ?? 48 81 C4 38 01 00 00 C3 } |
Condition
uint16( 0 ) == 0x5a4d and any of themIn plain words (Heuristic)
- The file must start with “MZ” — a Windows executable (PE).
- At least one pattern in the rule must match.
Test this rule in your browser
Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.
Sample hashes
Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).
- 793dcc731fa2c6f7406fd52c7ac43926ac23e39badce09677128cce0192e19b0
Licence & attribution
Author: McAfee ATR Team
Source repository: Trellix Advanced Research Center @ 1919562a59
Licence: Apache License 2.0 (repository licence)
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: 38ab069d-b030-5459-a42f-7ecd5963e68f
Metadata
| rule_version | v1 |
|---|---|
| malware_type | ransomware |
| malware_family | Ransomware:W32/Exorcist |
| actor_type | Cybercrime |
| actor_type | Cybercrime |
| actor_group | Unknown |
Tags:RANSOMWAREFILE
Related rules
- MalwareTrellix Advanced Research Center· McAfee ATR Team· 2020-10-02
- MalwareTrellix Advanced Research Center· McAfee ATR Team· 2020-10-02
- MalwareTrellix Advanced Research Center· McAfee ATR Team· 2020-07-27
- MalwareTrellix Advanced Research Center· McAfee ATR Team· 2020-02-20
- MalwareTrellix Advanced Research Center· McAfee ATR Team· 2020-04-25
- MalwareTrellix Advanced Research Center· McAfee ATR Team· 2020-03-30
- MalwareTrellix Advanced Research Center· Marc Rivero | McAfee ATR Team· 2026-09-01
- MalwareTrellix Advanced Research Center· Marc Rivero | McAfee ATR Team· 2026-09-01