FE_APT_Backdoor_Linux32_SLOWPULSE_1

YARA-2025-1135 High general Active
No description available for this rule
FE_APT_Backdoor_Linux32_SLOWPULSE_1.yar Valid Syntax
// Copyright 2021 by FireEye, Inc.
// You may not use this file except in compliance with the license. The license should have been received with this file.

rule FE_APT_Backdoor_Linux32_SLOWPULSE_1 
{ 
    meta: 
        author = "Mandiant" 
        date_created = "2021-04-16"
        sha256 = "cd09ec795a8f4b6ced003500a44d810f49943514e2f92c81ab96c33e1c0fbd68"
        reference_url = "https://www.fireeye.com/blog/threat-research/2021/04/suspected-apt-actors-leverage-bypass-techniques-pulse-secure-zero-day.html"        
    strings: 
        $sb1 = {FC b9 [4] e8 00 00 00 00 5? 8d b? [4] 8b} 
        $sb2 = {f3 a6 0f 85 [4] b8 03 00 00 00 5? 5? 5?} 
        $sb3 = {9c 60 e8 00 00 00 00 5? 8d [5] 85 ?? 0f 8?} 
        $sb4 = {89 13 8b 51 04 89 53 04 8b 51 08 89 53 08} 
        $sb5 = {8d [5] b9 [4] f3 a6 0f 8?} 
    condition: 
        ((uint32(0) == 0x464c457f) and (uint8(4) == 1)) and all of them 
}

Rule Metadata

author
Mandiant
date_created
2021-04-16
sha256
cd09ec795a8f4b6ced003500a44d810f49943514e2f92c81ab96c33e1c0fbd68
reference_url
https://www.fireeye.com/blog/threat-research/2021/04/suspected-apt-actors-leverage-bypass-techniques-pulse-secure-zero-day.html

String Definitions

{"name":"$sb1","value":"{FC b9 [4] e8 00 00 00 00 5? 8d b? [4] 8b}"}
{"name":"$sb2","value":"{f3 a6 0f 85 [4] b8 03 00 00 00 5? 5? 5?}"}
{"name":"$sb3","value":"{9c 60 e8 00 00 00 00 5? 8d [5] 85 ?? 0f 8?}"}
{"name":"$sb4","value":"{89 13 8b 51 04 89 53 04 8b 51 08 89 53 08}"}
{"name":"$sb5","value":"{8d [5] b9 [4] f3 a6 0f 8?}"}

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 FE_APT_Backdoor_Linux32_SLOWPULSE_1.yar /path/to/suspicious/file

# Scan a directory recursively
yara -r FE_APT_Backdoor_Linux32_SLOWPULSE_1.yar /path/to/directory/

# Scan with metadata output
yara -m FE_APT_Backdoor_Linux32_SLOWPULSE_1.yar target_file

# Scan process memory (Linux)
yara FE_APT_Backdoor_Linux32_SLOWPULSE_1.yar /proc/[pid]/exe

Integration Examples

Python (yara-python)

import yara
rules = yara.compile(filepath='FE_APT_Backdoor_Linux32_SLOWPULSE_1.yar')
matches = rules.match('/path/to/file')

ClamAV Integration

clamscan --yara-rules=FE_APT_Backdoor_Linux32_SLOWPULSE_1.yar /path/to/scan

Rule Information

YARA ID
YARA-2025-1135
Author
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