YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_Hvs_APT37_Cred_Tool

Unknown cred tool used by APT37

APT / threat actorSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X

Author: Markus Poelloth
Date: 2020-12-15
Modified: 2023-12-05
Score / Quality: 75 / 85

What this rule detects

Unknown cred tool used by APT37

It defines 8 patterns (8 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

hvs-apt37-cred-tool.yarDetection Rule License 1.1

rule SIGNATURE_BASE_Hvs_APT37_Cred_Tool : FILE
{
	meta:
		description = "Unknown cred tool used by APT37"
		author = "Markus Poelloth"
		id = "e830025a-f2ac-55b1-aca3-ded9dba83a67"
		date = "2020-12-15"
		modified = "2023-12-05"
		reference = "https://www.hvs-consulting.de/media/downloads/ThreatReport-Lazarus.pdf"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_lazarus_dec20.yar#L31-L50"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "4fb7247b88f2d252e7c9d5034c209945bc9e17f49de3dcdb5bf50b5afb302987"
		score = 75
		quality = 85
		tags = "FILE"
		license = "Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE"

	strings:
		$s1 = "        <requestedExecutionLevel level=\"asInvoker\" uiAccess=\"false\"></requestedExecutionLevel>" fullword ascii
		$s2 = "Domain Login" fullword ascii
		$s3 = "IEShims_GetOriginatingThreadContext" fullword ascii
		$s4 = " Type Descriptor'" fullword ascii
		$s5 = "User: %s" fullword ascii
		$s6 = "Pass: %s" fullword ascii
		$s7 = "  <trustInfo xmlns=\"urn:schemas-microsoft-com:asm.v3\">" fullword ascii
		$s8 = "E@c:\\u" fullword ascii

	condition:
		filesize < 500KB and 7 of them
}

Strings (8 patterns)

Identifier	Type	Value	Modifiers
$s1	text	" <requestedExecutionLevel level=\"asInvoker\" uiAccess=\"false\"></requestedExecutionLevel>"	fullword ascii
$s2	text	"Domain Login"	fullword ascii
$s3	text	"IEShims_GetOriginatingThreadContext"	fullword ascii
$s4	text	" Type Descriptor'"	fullword ascii
$s5	text	"User: %s"	fullword ascii
$s6	text	"Pass: %s"	fullword ascii
$s7	text	" <trustInfo xmlns=\"urn:schemas-microsoft-com:asm.v3\">"	fullword ascii
$s8	text	"E@c:\\u"	fullword ascii

Condition

filesize < 500KB and 7 of them

In plain words (Heuristic)

The file must be smaller than 500KB (a cheap guard that skips large files).
At least 7 patterns in the rule must match.

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References

https://www.hvs-consulting.de/media/downloads/ThreatReport-Lazarus.pdf

Licence & attribution

Author: Markus Poelloth

Source repository: Signature Base (Florian Roth / Nextron) @ 94a1c48d7a

Licence: Detection Rule License 1.1 (stated in the rule's own meta)

“Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE”

Original rule

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

Rule id: e830025a-f2ac-55b1-aca3-ded9dba83a67

Tags:FILE