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EMBEERESEARCH_Win_Lumma_Update_Simple_Strings_Sep_2023

MalwareLummaEmbee ResearchDetection Rule License 1.1Compiles with YARA-X
Author
Matthew @ Embee_Research
Date
2023-09-13
Modified
2023-09-21
Score / Quality
75 / 75

What this rule detects

Associated malware family: Lumma.

Targets: Windows PE.

It defines 4 patterns (4 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

win-lumma-update-simple-strings-sep-2023.yarDetection Rule License 1.1
rule EMBEERESEARCH_Win_Lumma_Update_Simple_Strings_Sep_2023 : FILE
{
	meta:
		description = ""
		author = "Matthew @ Embee_Research"
		id = "90209fc6-fd50-5b55-a400-112b2f207885"
		date = "2023-09-13"
		modified = "2023-09-21"
		reference = "https://github.com/embee-research/Yara-detection-rules/"
		source_url = "https://github.com/embee-research/Yara-detection-rules//blob/ac56d6f6fd2a30c8cb6e5c0455d6519210a8b0f4/Rules/win_lumma_updated_sep_2023.yar#L1-L25"
		license_url = "N/A"
		hash = "898a2bdbbb33ccd63b038c67d217554a668a52e9642874bd0f57e08153e6e5be"
		logic_hash = "61571057a5a9c114b6ed5b94b922f2b389406a05e705b3e9e6ddbee221f74c92"
		score = 75
		quality = 75
		tags = "FILE"

	strings:
		$s1 = "Do you want to run a malware ?" wide
		$s2 = "c2sock" wide
		$s3 = "TeslaBrowser/5" wide
		$s4 = "Crypt build to disable this message" wide

	condition:
		uint16( 0 ) == 0x5a4d and filesize < 5000KB and ( all of ( $s* ) )
}

Strings (4 patterns)

IdentifierTypeValueModifiers
$s1text"Do you want to run a malware ?"wide
$s2text"c2sock"wide
$s3text"TeslaBrowser/5"wide
$s4text"Crypt build to disable this message"wide

Condition

uint16( 0 ) == 0x5a4d and filesize < 5000KB and ( all of ( $s* ) )

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • The file must be smaller than 5000KB (a cheap guard that skips large files).
  • All patterns in ( $s* ) must match.

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References

Sample hashes

Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).

  • 898a2bdbbb33ccd63b038c67d217554a668a52e9642874bd0f57e08153e6e5be

Licence & attribution

Author: Matthew @ Embee_Research

Source repository: Embee Research @ ac56d6f6fd

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: 90209fc6-fd50-5b55-a400-112b2f207885

Tags:FILE

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