Skip to content

YARA · SEKOIA.IO Community

SEKOIA_Strongpity_Malware

Detects obfuscation used by StrongPity

MalwareStrongpitySEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X
Author
Sekoia.io
Date
2024-02-26
Modified
2024-12-19
Score / Quality
75 / 80

What this rule detects

Detects obfuscation used by StrongPity

Associated malware family: Strongpity.

Targets: Windows PE.

It defines 3 patterns (0 text, 3 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

strongpity-malware.yarDetection Rule License 1.1
rule SEKOIA_Strongpity_Malware : FILE
{
	meta:
		description = "Detects obfuscation used by StrongPity"
		author = "Sekoia.io"
		id = "f19a685c-599d-42cf-a5d8-7a2375102f97"
		date = "2024-02-26"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/strongpity_malware.yar#L1-L21"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "14be5eccb4e754d6dad69cda51a924241cc75f5d758bc2d746acfe41e1684b3a"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$rand_edi = {E8 ?? ?? ?? ??    8B F8 81 E7 07 00 00 80    79 ?? 4F 83 CF F8 47 83 C7 02}
		$rand_esi = {E8 ?? ?? ?? ?? 8B F0 81 E6 07 00 00 80 79 ?? 4E 83 CE F8 46 83 C6 02}
		$rand_eax = {E8 ?? ?? ?? ??    25 07 00 00 80 79 ?? 48 83 C8 F8 40 83 C0 02}

	condition:
		uint16be( 0 ) == 0x4d5a and #rand_edi + #rand_esi + #rand_eax > 20
}

Strings (3 patterns)

IdentifierTypeValueModifiers
$rand_edihex{E8 ?? ?? ?? ?? 8B F8 81 E7 07 00 00 80 79 ?? 4F 83 CF F8 47 83 C7 02}
$rand_esihex{E8 ?? ?? ?? ?? 8B F0 81 E6 07 00 00 80 79 ?? 4E 83 CE F8 46 83 C6 02}
$rand_eaxhex{E8 ?? ?? ?? ?? 25 07 00 00 80 79 ?? 48 83 C8 F8 40 83 C0 02}

Condition

uint16be( 0 ) == 0x4d5a and #rand_edi + #rand_esi + #rand_eax > 20

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • Pattern $rand_eax must occur > 20 times.

Test this rule in your browser

Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.

Drop a file here or click to chooseScanned locally with YARA-X. Files up to 200 MB.

Open in editor

References

Licence & attribution

Author: Sekoia.io

Source repository: SEKOIA.IO Community @ a438a5901a

Licence: Detection Rule License 1.1 (repository licence)

Original rule

Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.

Rule id: f19a685c-599d-42cf-a5d8-7a2375102f97

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE

More Strongpity rules