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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_Hvs_APT37_Smb_Scanner

Unknown smb login scanner used by APT37

APT / threat actorSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Marc Stroebel
Date
2020-12-15
Modified
2023-12-05
Score / Quality
75 / 85

What this rule detects

Unknown smb login scanner used by APT37

Targets: Windows PE.

It defines 15 patterns (15 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

hvs-apt37-smb-scanner.yarDetection Rule License 1.1
rule SIGNATURE_BASE_Hvs_APT37_Smb_Scanner : FILE
{
	meta:
		description = "Unknown smb login scanner used by APT37"
		author = "Marc Stroebel"
		id = "89a5cc32-f151-583d-823d-692de2c2b084"
		date = "2020-12-15"
		modified = "2023-12-05"
		reference = "https://www.hybrid-analysis.com/sample/d16163526242508d6961f061aaffe3ae5321bd64d8ceb6b2788f1570757595fc?environmentId=2"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_lazarus_dec20.yar#L2-L29"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "0bea71db7052f1c22c01cfbf710d4ed24651cbbd8b0fd29f09dfd49c4e314028"
		score = 75
		quality = 85
		tags = "FILE"
		license = "Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE"

	strings:
		$s1 = "Scan.exe StartIP EndIP ThreadCount logfilePath [Username Password Deep]" fullword ascii
		$s2 = "%s - %s:(Username - %s / Password - %s" fullword ascii
		$s3 = "Load mpr.dll Error " fullword ascii
		$s4 = "Load Netapi32.dll Error " fullword ascii
		$s5 = "%s U/P not Correct! - %d" fullword ascii
		$s6 = "GetNetWorkInfo Version 1.0" fullword wide
		$s7 = "Hello World!" fullword wide
		$s8 = "%s Error: %ld" fullword ascii
		$s9 = "%s U/P Correct!" fullword ascii
		$s10 = "%s --------" fullword ascii
		$s11 = "%s%-30s%I64d" fullword ascii
		$s12 = "%s%-30s(DIR)" fullword ascii
		$s13 = "%04d-%02d-%02d %02d:%02d" fullword ascii
		$s14 = "Share:              Local Path:                   Uses:   Descriptor:" fullword ascii
		$s15 = "Share:              Type:                   Remark:" fullword ascii

	condition:
		uint16( 0 ) == 0x5a4d and filesize < 200KB and ( 10 of them )
}

Strings (15 patterns)

IdentifierTypeValueModifiers
$s1text"Scan.exe StartIP EndIP ThreadCount logfilePath [Username Password Deep]"fullword ascii
$s2text"%s - %s:(Username - %s / Password - %s"fullword ascii
$s3text"Load mpr.dll Error "fullword ascii
$s4text"Load Netapi32.dll Error "fullword ascii
$s5text"%s U/P not Correct! - %d"fullword ascii
$s6text"GetNetWorkInfo Version 1.0"fullword wide
$s7text"Hello World!"fullword wide
$s8text"%s Error: %ld"fullword ascii
$s9text"%s U/P Correct!"fullword ascii
$s10text"%s --------"fullword ascii
$s11text"%s%-30s%I64d"fullword ascii
$s12text"%s%-30s(DIR)"fullword ascii
$s13text"%04d-%02d-%02d %02d:%02d"fullword ascii
$s14text"Share: Local Path: Uses: Descriptor:"fullword ascii
$s15text"Share: Type: Remark:"fullword ascii

Condition

uint16( 0 ) == 0x5a4d and filesize < 200KB and ( 10 of them )

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • The file must be smaller than 200KB (a cheap guard that skips large files).
  • At least 10 patterns in the rule must match.

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

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References

Licence & attribution

Author: Marc Stroebel

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: 89a5cc32-f151-583d-823d-692de2c2b084

Tags:FILE