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YARA · Volexity threat-intel

VOLEXITY_Malware_Win_Backwash_Cpp

CPP loader for the Backwash malware.

MalwareVolexity threat-intelBSD 2-Clause LicenseCompiles with YARA-X
Author
threatintel@volexity.com
Date
2021-11-17
Modified
2023-11-13
Score / Quality
75 / 80

What this rule detects

CPP loader for the Backwash malware.

It defines 3 patterns (3 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

malware-win-backwash-cpp.yarBSD 2-Clause License
rule VOLEXITY_Malware_Win_Backwash_Cpp : WHEELEDASH FILE MEMORY
{
	meta:
		description = "CPP loader for the Backwash malware."
		author = "threatintel@volexity.com"
		id = "8a1c4ff1-1827-5e6f-b838-664d8c3be840"
		date = "2021-11-17"
		modified = "2023-11-13"
		reference = "https://github.com/volexity/threat-intel"
		source_url = "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/2021/2021-12-06 - XEGroup/indicators/yara.yar#L3-L26"
		license_url = "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/LICENSE.txt"
		hash = "0cf93de64aa4dba6cec99aa5989fc9c5049bc46ca5f3cb327b49d62f3646a852"
		logic_hash = "c8ed2d3103aa85363acd7f5573aeb936a5ab5a3bacbcf1f04e6b298299f24dae"
		score = 75
		quality = 80
		tags = "WHEELEDASH, FILE, MEMORY"
		os = "win"
		os_arch = "all"
		scan_context = "file,memory"
		severity = "critical"
		license = "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt"
		rule_id = 6147
		version = 2

	strings:
		$s1 = "cor1dbg.dll" wide
		$s2 = "XEReverseShell.exe" wide
		$s3 = "XOJUMAN=" wide

	condition:
		2 of them
}

Strings (3 patterns)

IdentifierTypeValueModifiers
$s1text"cor1dbg.dll"wide
$s2text"XEReverseShell.exe"wide
$s3text"XOJUMAN="wide

Condition

2 of them

In plain words (Heuristic)

  • At least 2 patterns in the rule 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).

  • 0cf93de64aa4dba6cec99aa5989fc9c5049bc46ca5f3cb327b49d62f3646a852

Licence & attribution

Author: threatintel@volexity.com

Source repository: Volexity threat-intel @ 3a9d0b5245

Licence: BSD 2-Clause License (stated in the rule's own meta)

“See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt”

Copyright notice: Copyright 2022 by Volexity, Inc.

Original rule

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

Rule id: 8a1c4ff1-1827-5e6f-b838-664d8c3be840

Metadata

oswin
os_archall
scan_contextfile,memory
severitycritical
rule_id6147
version2

Tags:WHEELEDASHFILEMEMORY