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DITEKSHEN_MALWARE_Win_Brbbot

Detects BrbBot

MalwareBrbbotditekSHen detectionBSD 2-Clause LicenseCompiles with YARA-X
Author
ditekSHen
Date
2020-11-06
Modified
2024-11-01
Score / Quality
75 / 75

What this rule detects

Detects BrbBot

Associated malware family: Brbbot.

Targets: Windows PE.

It defines 7 patterns (6 text, 1 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
malware-win-brbbot.yarBSD 2-Clause License
rule DITEKSHEN_MALWARE_Win_Brbbot : FILE
{
	meta:
		description = "Detects BrbBot"
		author = "ditekSHen"
		id = "d77dfdcf-4cd5-578e-99eb-c987e7b5b706"
		date = "2020-11-06"
		modified = "2024-11-01"
		reference = "https://github.com/ditekshen/detection"
		source_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/yara/malware.yar#L8327-L8345"
		license_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/LICENSE.txt"
		logic_hash = "64df5bba698fbba1baf27eedb9a2eb46c5e0752996ea91900f8377200d54eeeb"
		score = 75
		quality = 75
		tags = "FILE"
		snort_sid = "920265"

	strings:
		$x1 = "brbconfig.tmp" fullword ascii
		$x2 = "brbbot" fullword ascii
		$s1 = "%s?i=%s&c=%s&p=%s" fullword ascii
		$s2 = "exec" fullword ascii
		$s3 = "CONFIG" fullword ascii wide
		$s4 = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0)" fullword ascii
		$s5 = { 43 4f 4e 46 49 47 00 00 65 6e 63 6f 64 65 00 00
                73 6c 65 65 70 00 00 00 65 78 69 74 00 00 00 00
                63 6f 6e 66 00 00 00 00 66 69 6c 65 00 00 00 00
                65 78 65 63 }

	condition:
		uint16( 0 ) == 0x5a4d and ( ( all of ( $x* ) and 1 of ( $s* ) ) or ( 1 of ( $x* ) and 4 of ( $s* ) ) or all of ( $s* ) )
}

Strings (7 patterns)

IdentifierTypeValueModifiers
$x1text"brbconfig.tmp"fullword ascii
$x2text"brbbot"fullword ascii
$s1text"%s?i=%s&c=%s&p=%s"fullword ascii
$s2text"exec"fullword ascii
$s3text"CONFIG"fullword ascii wide
$s4text"Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0)"fullword ascii
$s5hex{ 43 4f 4e 46 49 47 00 00 65 6e 63 6f 64 65 00 00 73 6c 65 65 70 00 00 00 65 78 69 74 00 00 00 00 63 6f 6e 66 00 00 00 00 66 69 …

Condition

uint16( 0 ) == 0x5a4d and ( ( all of ( $x* ) and 1 of ( $s* ) ) or ( 1 of ( $x* ) and 4 of ( $s* ) ) or all of ( $s* ) )

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • All patterns in ( $x* ) must match.
  • All patterns in ( $s* ) must match.
  • At least 1 patterns in ( $s* ) must match.
  • At least 1 patterns in ( $x* ) must match.
  • At least 4 patterns in ( $s* ) must match.

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References

Licence & attribution

Author: ditekSHen

Source repository: ditekSHen detection @ e76c93dcde

Licence: BSD 2-Clause License (repository licence)

Copyright notice: Copyright 2021 by ditekSHen (https://github.com/ditekshen/detection).

Original rule

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

Rule id: d77dfdcf-4cd5-578e-99eb-c987e7b5b706

Metadata

snort_sid920265

Tags:FILE

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