Possible_Solarmarker_Backdoor_Nov2023

YARA-2025-0133 High general Active
No description available for this rule
Possible_Solarmarker_Backdoor_Nov2023.yar Valid Syntax
/*
 This Yara ruleset is under the GNU-GPLv2 license (http://www.gnu.org/licenses/gpl-2.0.html) and open to any user or organization, as long as you use it under this license.
*/
rule Possible_Solarmarker_Backdoor_Nov2023
{
   meta:
        author = "Lucas Acha (http://www.lukeacha.com)"
        description = "Observed strings in the latest obfuscated solarmarker backdoor dll."
        reference = "https://security5magics.blogspot.com/2023/10/new-solarmarker-variant-october-2023.html" 
  strings:
    $a = /\x00<Module>\x00[a-zA-Z0-9]{40}/ ascii
    $h1 = {54 68 72 65 61 64 00 53 6C 65 65 70}
    $h2 = {54 68 72 65 61 64 00 53 74 61 72 74}
    $b = /\x00Select\x00[a-zA-Z0-9_]{40}/ ascii
    $c = "GenerateIV" ascii
    $d = "$$method0x" ascii
  condition:
    $a and $b and $c and $d and ($h1 or $h2)
}

Rule Metadata

author
Lucas Acha (http://www.lukeacha.com)

String Definitions

{"name":"$a","value":"\/\\x00<Module>\\x00[a-zA-Z0-9]{40}\/ ascii"}
{"name":"$h1","value":"{54 68 72 65 61 64 00 53 6C 65 65 70}"}
{"name":"$h2","value":"{54 68 72 65 61 64 00 53 74 61 72 74}"}
{"name":"$b","value":"\/\\x00Select\\x00[a-zA-Z0-9_]{40}\/ ascii"}
{"name":"$c","value":"\"GenerateIV\" ascii"}
{"name":"$d","value":"\""}

Threat Analysis

This YARA rule is designed to detect general threats.

Severity Level: High

The rule uses pattern matching to identify specific byte sequences, strings, or behavioral patterns associated with malicious activity.

Detection Capabilities

  • File-based detection for executables and documents
  • Memory scanning for running processes
  • Network traffic analysis support

Command Line Usage

# Scan a single file
yara Possible_Solarmarker_Backdoor_Nov2023.yar /path/to/suspicious/file

# Scan a directory recursively
yara -r Possible_Solarmarker_Backdoor_Nov2023.yar /path/to/directory/

# Scan with metadata output
yara -m Possible_Solarmarker_Backdoor_Nov2023.yar target_file

# Scan process memory (Linux)
yara Possible_Solarmarker_Backdoor_Nov2023.yar /proc/[pid]/exe

Integration Examples

Python (yara-python)

import yara
rules = yara.compile(filepath='Possible_Solarmarker_Backdoor_Nov2023.yar')
matches = rules.match('/path/to/file')

ClamAV Integration

clamscan --yara-rules=Possible_Solarmarker_Backdoor_Nov2023.yar /path/to/scan

Rule Information

YARA ID
YARA-2025-0133
Created
August 19, 2025
Last Updated
August 19, 2025
Last Imported
Never

Threat Intelligence

Risk Level High
Category general
Detection Confidence Analysis Pending
False Positive Rate Not Available
Last Seen in Wild No Data

Export Options