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SEKOIA_Nomercy

Detect NoMercy sample version up to 1.1.0

GenericSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X
Author
Sekoia.io
Date
2022-07-11
Modified
2024-12-19
Score / Quality
75 / 78

What this rule detects

Detect NoMercy sample version up to 1.1.0

Targets: Windows PE.

It defines 37 patterns (37 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
nomercy.yarDetection Rule License 1.1
rule SEKOIA_Nomercy : FILE
{
	meta:
		description = "Detect NoMercy sample version up to 1.1.0"
		author = "Sekoia.io"
		id = "2591f74b-8ab8-45ef-ba64-62a93df305c1"
		date = "2022-07-11"
		modified = "2024-12-19"
		reference = "https://blog.cyble.com/2022/07/07/nomercy-stealer-adding-new-features/"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/nomercy.yar#L1-L61"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		hash = "9ecc76d4cda47a93681ddbb67b642c2e1f303ab834160ab94b79b47381e23a65"
		hash = "557acce8b787aba87c8eeb939438b52c5ca953f28ad680a7faeb2b3046d3fda0"
		logic_hash = "175bc58f1b34bb60f6cacc15747e944cbbdd58fe287ff46abed969eaa39870db"
		score = 75
		quality = 78
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$debug1 = "Posted uid and version" wide ascii
		$debug2 = "Posted cli info to server" wide ascii
		$debug3 = "Posted other info to server" wide ascii
		$debug4 = "Sending screenshot..." wide ascii
		$debug5 = "Sent screenshot" wide ascii
		$debug6 = "Listening to Microphone..." wide ascii
		$debug7 = "Collecting other info..." wide ascii
		$url1 = "/a?uid=" wide ascii
		$url2 = "/c?uid=" wide ascii
		$url3 = "/d?uid=" wide ascii
		$url4 = "/e?uid=" wide ascii
		$url5 = "/b?sysinfoother=" wide ascii
		$url6 = "/b?sysinfocli=" wide ascii
		$info1 = "PUBLIC IP:" wide ascii
		$info2 = "HWID:" wide ascii
		$info3 = "RAM:" wide ascii
		$info4 = "GPU:" wide ascii
		$info5 = "MEDIA ACCESS CONTROL ADDRESS:" wide ascii
		$info6 = "PRIVATE IP:" wide ascii
		$info7 = "OS VERSION:" wide ascii
		$info8 = "ANTIVIRUS:" wide ascii
		$info9 = "KEYBOARD LANGUAGE:" wide ascii
		$info10 = "CLIPBOARD: {0}{1}{2}" wide ascii
		$info11 = "RUNNING PROCESSES:" wide ascii
		$info12 = "WINDOW TITLE:" wide ascii
		$cmd1 = "/c whoami /all" wide ascii
		$cmd2 = "/c whoami" wide ascii
		$cmd3 = "/c arp -a" wide ascii
		$cmd4 = "/c ipconfig /all" wide ascii
		$cmd5 = "/c net view /all" wide ascii
		$cmd6 = "/c net share" wide ascii
		$cmd7 = "/c route print" wide ascii
		$cmd8 = "/c netstat -nao" wide ascii
		$cmd9 = "/c net localgroup" wide ascii
		$cmd10 = "/c systeminfo" wide ascii
		$inv1 = "http://api.ipify.org" wide ascii
		$inv2 = "NoMercy" wide ascii

	condition:
		uint16be( 0 ) == 0x4d5a and 3 of ( $debug* ) and 8 of ( $info* ) and 2 of ( $url* ) and 6 of ( $cmd* ) and 1 of ( $inv* ) and filesize > 700KB and filesize < 3000KB
}

Strings (37 patterns)

IdentifierTypeValueModifiers
$debug1text"Posted uid and version"wide ascii
$debug2text"Posted cli info to server"wide ascii
$debug3text"Posted other info to server"wide ascii
$debug4text"Sending screenshot..."wide ascii
$debug5text"Sent screenshot"wide ascii
$debug6text"Listening to Microphone..."wide ascii
$debug7text"Collecting other info..."wide ascii
$url1text"/a?uid="wide ascii
$url2text"/c?uid="wide ascii
$url3text"/d?uid="wide ascii
$url4text"/e?uid="wide ascii
$url5text"/b?sysinfoother="wide ascii
$url6text"/b?sysinfocli="wide ascii
$info1text"PUBLIC IP:"wide ascii
$info2text"HWID:"wide ascii
$info3text"RAM:"wide ascii
$info4text"GPU:"wide ascii
$info5text"MEDIA ACCESS CONTROL ADDRESS:"wide ascii
$info6text"PRIVATE IP:"wide ascii
$info7text"OS VERSION:"wide ascii
$info8text"ANTIVIRUS:"wide ascii
$info9text"KEYBOARD LANGUAGE:"wide ascii
$info10text"CLIPBOARD: {0}{1}{2}"wide ascii
$info11text"RUNNING PROCESSES:"wide ascii
$info12text"WINDOW TITLE:"wide ascii
$cmd1text"/c whoami /all"wide ascii
$cmd2text"/c whoami"wide ascii
$cmd3text"/c arp -a"wide ascii
$cmd4text"/c ipconfig /all"wide ascii
$cmd5text"/c net view /all"wide ascii
$cmd6text"/c net share"wide ascii
$cmd7text"/c route print"wide ascii
$cmd8text"/c netstat -nao"wide ascii
$cmd9text"/c net localgroup"wide ascii
$cmd10text"/c systeminfo"wide ascii
$inv1text"http://api.ipify.org"wide ascii
$inv2text"NoMercy"wide ascii

Condition

uint16be( 0 ) == 0x4d5a and 3 of ( $debug* ) and 8 of ( $info* ) and 2 of ( $url* ) and 6 of ( $cmd* ) and 1 of ( $inv* ) and filesize > 700KB and filesize < 3000KB

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • The file must be smaller than 3000KB (a cheap guard that skips large files).
  • The file must be larger than 700KB.
  • At least 3 patterns in ( $debug* ) must match.
  • At least 8 patterns in ( $info* ) must match.
  • At least 2 patterns in ( $url* ) must match.
  • At least 6 patterns in ( $cmd* ) must match.
  • At least 1 patterns in ( $inv* ) 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).

  • 9ecc76d4cda47a93681ddbb67b642c2e1f303ab834160ab94b79b47381e23a65
  • 557acce8b787aba87c8eeb939438b52c5ca953f28ad680a7faeb2b3046d3fda0

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: 2591f74b-8ab8-45ef-ba64-62a93df305c1

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE

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