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SEKOIA_Tool_Ssf_Strings

Detects SSF based on strings

Hack toolSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X
Author
Sekoia.io
Date
2024-05-31
Modified
2024-12-19
Score / Quality
75 / 80

What this rule detects

Detects SSF based on strings

Targets: Windows PE, Linux ELF.

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

Summary generated from the rule's metadata and condition.

Rule source

tool-ssf-strings.yarDetection Rule License 1.1
rule SEKOIA_Tool_Ssf_Strings : FILE
{
	meta:
		description = "Detects SSF based on strings"
		author = "Sekoia.io"
		id = "47fc3df8-a153-4045-a5f0-ed30df662984"
		date = "2024-05-31"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/tool_ssf_strings.yar#L1-L23"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "a6fa09a25c90e00466a2b59f8c604084996224c93021ad72ed8705bf05da5d97"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$ = "could NOT read SSF reply"
		$ = "SSF reply NOT ok {}"
		$ = "SSF reply OK"
		$ = "SSF protocol error {}"
		$ = "SSF reply ok"
		$ = "SSF version NOT read {}"
		$ = "SSF version {}"
		$ = "SSF version NOT supported {}"

	condition:
		( uint32be( 0 ) == 0x7f454c46 or uint16be( 0 ) == 0x4d5a ) and 4 of them
}

Strings (8 patterns)

IdentifierTypeValueModifiers
$text"could NOT read SSF reply"
$text"SSF reply NOT ok {}"
$text"SSF reply OK"
$text"SSF protocol error {}"
$text"SSF reply ok"
$text"SSF version NOT read {}"
$text"SSF version {}"
$text"SSF version NOT supported {}"

Condition

( uint32be( 0 ) == 0x7f454c46 or uint16be( 0 ) == 0x4d5a ) and 4 of them

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • The file must start with the ELF header — a Linux/Unix executable.
  • At least 4 patterns in the rule must match.

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References

Licence & attribution

Author: Sekoia.io

Source repository: SEKOIA.IO Community @ a438a5901a

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: 47fc3df8-a153-4045-a5f0-ed30df662984

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE