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YARA · CAPE Sandbox (CAPEv2)

CAPE_Loadersyscall

Loader Syscall

MalwareCAPE Sandbox (CAPEv2)GNU General Public License v3.0Compiles with YARA-X
Author
enzok
Date
2024-10-29
Modified
2025-07-23
Score / Quality
75 / 70

What this rule detects

Loader Syscall

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

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
loadersyscall.yarGNU General Public License v3.0
rule CAPE_Loadersyscall
{
	meta:
		description = "Loader Syscall"
		author = "enzok"
		id = "45193b38-938e-55cf-9ea0-7bd48f0d77e4"
		date = "2024-10-29"
		modified = "2025-07-23"
		reference = "https://github.com/kevoreilly/CAPEv2"
		source_url = "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/analyzer/windows/data/yara/NitrogenLoader.yar#L1-L13"
		license_url = "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/LICENSE"
		logic_hash = "3c7ffd8b95032cffecff7fa7e5f5f561cce13e1109f6a9b30bc743642b495e45"
		score = 75
		quality = 70
		tags = ""
		cape_options = "sysbp=$syscall*-2,count=0"

	strings:
		$makehashes = {48 89 4C 24 ?? 48 89 54 24 ?? 4? 89 44 24 ?? 4? 89 4C 24 ?? 4? 83 EC ?? B? [4] E8 [3] 00}
		$number = {49 89 C3 B? [4] E8 [3] 00}
		$syscall = {48 83 C4 ?? 4? 8B 4C 24 ?? 4? 8B 54 24 ?? 4? 8B 44 24 ?? 4? 8B 4C 24 ?? 4? 89 CA 4? FF E3}

	condition:
		all of them
}

Strings (3 patterns)

IdentifierTypeValueModifiers
$makehasheshex{48 89 4C 24 ?? 48 89 54 24 ?? 4? 89 44 24 ?? 4? 89 4C 24 ?? 4? 83 EC ?? B? [4] E8 [3] 00}
$numberhex{49 89 C3 B? [4] E8 [3] 00}
$syscallhex{48 83 C4 ?? 4? 8B 4C 24 ?? 4? 8B 54 24 ?? 4? 8B 44 24 ?? 4? 8B 4C 24 ?? 4? 89 CA 4? FF E3}

Condition

all of them

In plain words (Heuristic)

  • All patterns in the rule must match.

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References

Licence & attribution

Author: enzok

Source repository: CAPE Sandbox (CAPEv2) @ 6b15e76f28

Licence: GNU General Public License v3.0 (repository licence)

Copyright notice: Cuckoo Sandbox is copyrighted by the Cuckoo Foundation.

Original rule

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

Rule id: 45193b38-938e-55cf-9ea0-7bd48f0d77e4

Metadata

cape_optionssysbp=$syscall*-2,count=0

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