Zlib_Backdoor
YARA-2025-1178
High
general
Active
No description available for this rule
Zlib_Backdoor.yar
Valid Syntax
rule Zlib_Backdoor
{
meta:
author = "Cylance SPEAR Team"
/* String
C7 45 FC 00 04 00 00 mov [ebp+Memory], 400h
C6 45 D8 50 mov [ebp+Str], 'P'
C6 45 D9 72 mov [ebp+var_27], 'r'
C6 45 DA 6F mov [ebp+var_26], 'o'
C6 45 DB 78 mov [ebp+var_25], 'x'
C6 45 DC 79 mov [ebp+var_24], 'y'
C6 45 DD 2D mov [ebp+var_23], '-'
C6 45 DE 41 mov [ebp+var_22], 'A'
C6 45 DF 75 mov [ebp+var_21], 'u'
C6 45 E0 74 mov [ebp+var_20], 't'
C6 45 E1 68 mov [ebp+var_1F], 'h'
C6 45 E2 65 mov [ebp+var_1E], 'e'
C6 45 E3 6E mov [ebp+var_1D], 'n'
C6 45 E4 74 mov [ebp+var_1C], 't'
C6 45 E5 69 mov [ebp+var_1B], 'i'
C6 45 E6 63 mov [ebp+var_1A], 'c'
C6 45 E7 61 mov [ebp+var_19], 'a'
C6 45 E8 74 mov [ebp+var_18], 't'
C6 45 E9 65 mov [ebp+var_17], 'e'
C6 45 EA 3A mov [ebp+var_16], ':'
C6 45 EB 20 mov [ebp+var_15], ' '
C6 45 EC 4E mov [ebp+var_14], 'N'
C6 45 ED 54 mov [ebp+var_13], 'T'
C6 45 EE 4C mov [ebp+var_12], 'L'
C6 45 EF 4D mov [ebp+var_11], 'M'
C6 45 F0 20 mov [ebp+var_10], ' '
*/
strings:
$auth = {C6 45 D8 50 C6 45 D9 72 C6 45 DA 6F C6 45 DB 78 C6 45 DC 79 C6 45 DD 2D}
$auth2 = {C7 45 FC 00 04 00 00 C6 45 ?? 50 C6 45 ?? 72 C6 45 ?? 6F}
$ntlm = "NTLM" wide
condition:
($auth or $auth2) and $ntlm
}Rule Metadata
author
Cylance SPEAR Team
String Definitions
{"name":"$auth","value":"{C6 45 D8 50 C6 45 D9 72 C6 45 DA 6F C6 45 DB 78 C6 45 DC 79 C6 45 DD 2D}"}
{"name":"$auth2","value":"{C7 45 FC 00 04 00 00 C6 45 ?? 50 C6 45 ?? 72 C6 45 ?? 6F}"}
{"name":"$ntlm","value":"\"NTLM\" wide"}
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 Zlib_Backdoor.yar /path/to/suspicious/file # Scan a directory recursively yara -r Zlib_Backdoor.yar /path/to/directory/ # Scan with metadata output yara -m Zlib_Backdoor.yar target_file # Scan process memory (Linux) yara Zlib_Backdoor.yar /proc/[pid]/exe
Integration Examples
Python (yara-python)
import yara
rules = yara.compile(filepath='Zlib_Backdoor.yar')
matches = rules.match('/path/to/file')
ClamAV Integration
clamscan --yara-rules=Zlib_Backdoor.yar /path/to/scan
Rule Information
YARA ID
YARA-2025-1178
Author
Repository
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
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