Skip to content

YARA · Embee Research

EMBEERESEARCH_Win_Exela_Stealer_Simple_Strings_Sep_2023

No description has been set in the source file - EmbeeResearch

MalwareEmbee ResearchDetection Rule License 1.1Compiles with YARA-X
Author
Matthew @embee_research
Date
2023-09-24
Modified
2023-09-26
Score / Quality
75 / 75

What this rule detects

No description has been set in the source file - EmbeeResearch

Targets: .NET assembly.

It defines 10 patterns (10 text, 0 hex, 0 regex). YARA modules used: dotnet.

Summary generated from the rule's metadata and condition.

Rule source

Includes the imports needed to compile it on its own.

win-exela-stealer-simple-strings-sep-2023.yarDetection Rule License 1.1
import "dotnet"

rule EMBEERESEARCH_Win_Exela_Stealer_Simple_Strings_Sep_2023
{
	meta:
		description = "No description has been set in the source file - EmbeeResearch"
		author = "Matthew @embee_research"
		id = "e63aa1d3-997e-5200-93fc-869c177fe1a8"
		date = "2023-09-24"
		modified = "2023-09-26"
		reference = "https://github.com/embee-research/Yara-detection-rules/"
		source_url = "https://github.com/embee-research/Yara-detection-rules//blob/ac56d6f6fd2a30c8cb6e5c0455d6519210a8b0f4/Rules/win_exela_stealer_simple_strings_sep_2023.yar#L4-L32"
		license_url = "N/A"
		hash = "bf5d70ca2faf355d86f4b40b58032f21e99c3944b1c5e199b9bb728258a95c1b"
		logic_hash = "2312b63fe86fd34eb12f42f079f470eb3af27ef8c199f3620253c828ad28441a"
		score = 75
		quality = 75
		tags = ""

	strings:
		$s1 = "https://i.instagram.com/api/v1/accounts/current_user/" wide
		$s2 = "/create /f /sc onlogon /rl highest /tn \"AutoUpdateCheckerOnLogon\" /tr " wide
		$s4 = "https://discord.com/api/webhooks/" wide
		$s5 = "Browser : {0} | Name : {1} | Value : {2} | Date created (timestamp) : {3} |  Date last used (timestamp) : {4} | Count {5}" wide
		$s6 = "Browser : {0} | {1} {2}/{3} {4}" wide
		$e1 = "Exela.Program" wide ascii
		$e2 = "Exela.Wifi" wide ascii
		$e3 = "Exela.Components" wide ascii
		$e4 = "Exela Stealer" wide ascii
		$e5 = "Exela.exe" wide ascii

	condition:
		dotnet.is_dotnet and ( ( all of ( $s* ) ) or ( 3 of ( $e* ) ) )
}

Strings (10 patterns)

IdentifierTypeValueModifiers
$s1text"https://i.instagram.com/api/v1/accounts/current_user/"wide
$s2text"/create /f /sc onlogon /rl highest /tn \"AutoUpdateCheckerOnLogon\" /tr "wide
$s4text"https://discord.com/api/webhooks/"wide
$s5text"Browser : {0} | Name : {1} | Value : {2} | Date created (timestamp) : {3} | Date last used (timestamp) : {4} | Count {5}"wide
$s6text"Browser : {0} | {1} {2}/{3} {4}"wide
$e1text"Exela.Program"wide ascii
$e2text"Exela.Wifi"wide ascii
$e3text"Exela.Components"wide ascii
$e4text"Exela Stealer"wide ascii
$e5text"Exela.exe"wide ascii

Condition

dotnet.is_dotnet and ( ( all of ( $s* ) ) or ( 3 of ( $e* ) ) )

In plain words (Heuristic)

  • All patterns in ( $s* ) must match.
  • At least 3 patterns in ( $e* ) must match.
  • Uses the dotnet module.

Test this rule in your browser

Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.

Drop a file here or click to chooseScanned locally with YARA-X. Files up to 200 MB.

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).

  • bf5d70ca2faf355d86f4b40b58032f21e99c3944b1c5e199b9bb728258a95c1b

Licence & attribution

Author: Matthew @embee_research

Source repository: Embee Research @ ac56d6f6fd

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: e63aa1d3-997e-5200-93fc-869c177fe1a8