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YARA · CAPE Sandbox (CAPEv2)

CAPE_Agentteslav3Jit

AgentTesla V3 JIT native string decryption

MalwareAgentteslaCAPE Sandbox (CAPEv2)GNU General Public License v3.0Compiles with YARA-X
Author
ClaudioWayne
Date
2023-09-13
Modified
2024-02-27
Score / Quality
75 / 70

What this rule detects

AgentTesla V3 JIT native string decryption

Associated malware family: Agenttesla.

It defines 1 patterns (0 text, 1 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
agentteslav3jit.yarGNU General Public License v3.0
rule CAPE_Agentteslav3Jit
{
	meta:
		description = "AgentTesla V3 JIT native string decryption"
		author = "ClaudioWayne"
		id = "590c5058-c1db-5366-8db5-57449a178999"
		date = "2023-09-13"
		modified = "2024-02-27"
		reference = "https://github.com/kevoreilly/CAPEv2"
		source_url = "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/analyzer/windows/data/yara/AgentTesla.yar#L16-L26"
		license_url = "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/LICENSE"
		logic_hash = "62a49cf4295df637f96ba7c127cfc4aeb9af2fcced497fdf34d726a062edc1ec"
		score = 75
		quality = 70
		tags = ""
		cape_options = "bp0=$decode+20,count=0,action0=string:eax+8,typestring=AgentTesla Strings,no-logs=2"

	strings:
		$decode = {8B C8 57 FF 75 08 8B [5] 8B 01 8B 40 3C FF [2] 8B F0 B8 03 00 00 00}

	condition:
		all of them
}

Strings (1 patterns)

IdentifierTypeValueModifiers
$decodehex{8B C8 57 FF 75 08 8B [5] 8B 01 8B 40 3C FF [2] 8B F0 B8 03 00 00 00}

Condition

all of them

In plain words (Heuristic)

  • All patterns in the rule must match.

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References

Licence & attribution

Author: ClaudioWayne

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: 590c5058-c1db-5366-8db5-57449a178999

Metadata

cape_optionsbp0=$decode+20,count=0,action0=string:eax+8,typestring=AgentTesla Strings,no-logs=2

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