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TRELLIX_ARC_MALW_Fritzfrog

Rule to detect Fritzfrog

MalwareFritzfrogTrellix Advanced Research CenterApache License 2.0Compiles with YARA-X
Author
Marc Rivero | McAfee ATR Team
Date
2020-08-20
Score / Quality
75 / 70

What this rule detects

Rule to detect Fritzfrog

Associated malware family: Fritzfrog.

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

Summary generated from the rule's metadata and condition.

Rule source

malw-fritzfrog.yarApache License 2.0
rule TRELLIX_ARC_MALW_Fritzfrog : BOTNET FILE
{
	meta:
		description = "Rule to detect Fritzfrog"
		author = "Marc Rivero | McAfee ATR Team"
		id = "4c553279-7e0c-5602-944d-ad8a47edf4ea"
		date = "2020-08-20"
		modified = "2020-08-20"
		reference = "https://github.com/advanced-threat-research/Yara-Rules/"
		source_url = "https://github.com/advanced-threat-research/Yara-Rules//blob/1919562a59f190bda60c982424f6a24c542ee3e0/malware/MALW_fritzfrog.yar#L1-L26"
		license_url = "https://github.com/advanced-threat-research/Yara-Rules//blob/1919562a59f190bda60c982424f6a24c542ee3e0/LICENSE"
		hash = "103b8404dc64c9a44511675981a09fd01395ee837452d114f1350c295357c046"
		logic_hash = "488c807ecf0a9e981b2c1f2f5bb2e3072952d11f7cbf3a354bc85dc8e88b8b09"
		score = 75
		quality = 70
		tags = "BOTNET, FILE"
		rule_version = "v1"
		malware_type = "botnet"
		malware_family = "Botnet:W32/Fritzfrog"
		actor_type = "Cybercrime"
		actor_type = "Cybercrime"
		actor_group = "Unknown"

	strings:
		$pattern = { 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}

	condition:
		uint16( 0 ) == 0x457f and filesize < 26000KB and all of them
}

Strings (1 patterns)

IdentifierTypeValueModifiers
$patternhex{ 7F454C4602010100000000000000000002003E000100000090D34500000000004000000000000000C8010000000000000000000040003800070040000D000300060000000400000040000000000000 …

Condition

uint16( 0 ) == 0x457f and filesize < 26000KB and all of them

In plain words (Heuristic)

  • The file must be smaller than 26000KB (a cheap guard that skips large files).
  • All patterns in the rule must match.

Test this rule in your browser

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Open in editor

References

Sample hashes

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

  • 103b8404dc64c9a44511675981a09fd01395ee837452d114f1350c295357c046

Licence & attribution

Author: Marc Rivero | McAfee ATR Team

Source repository: Trellix Advanced Research Center @ 1919562a59

Licence: Apache License 2.0 (repository licence)

Original rule

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

Rule id: 4c553279-7e0c-5602-944d-ad8a47edf4ea

Metadata

rule_versionv1
malware_typebotnet
malware_familyBotnet:W32/Fritzfrog
actor_typeCybercrime
actor_typeCybercrime
actor_groupUnknown

Tags:BOTNETFILE