Windows_Ransomware_Cuba
YARA-2025-1299
Critical
general
Active
No description available for this rule
Windows_Ransomware_Cuba.yar
Valid Syntax
rule Windows_Ransomware_Cuba {
meta:
os = "Windows"
arch = "x86"
category_type = "Ransomware"
family = "Cuba"
threat_name = "Windows.Ransomware.Cuba"
Reference_sample = "33352a38454cfc247bc7465bf177f5f97d7fd0bd220103d4422c8ec45b4d3d0e"
Reference = "https://www.elastic.co/security-labs/cuba-ransomware-malware-analysis"
strings:
$a1 = { 45 EC 8B F9 8B 45 14 89 45 F0 8D 45 E4 50 8D 45 F8 66 0F 13 }
$a2 = { 8B 06 81 38 46 49 44 45 75 ?? 81 78 04 4C 2E 43 41 74 }
$b1 = "We also inform that your databases, ftp server and file server were downloaded by us to our servers." ascii fullword
$b2 = "Good day. All your files are encrypted. For decryption contact us." ascii fullword
$b3 = ".cuba" wide fullword
condition:
any of ($a*) or all of ($b*)
}
Rule Metadata
os
Windows
arch
x86
category_type
Ransomware
family
Cuba
threat_name
Windows.Ransomware.Cuba
Reference_sample
33352a38454cfc247bc7465bf177f5f97d7fd0bd220103d4422c8ec45b4d3d0e
Reference
https://www.elastic.co/security-labs/cuba-ransomware-malware-analysis
String Definitions
{"name":"$a1","value":"{ 45 EC 8B F9 8B 45 14 89 45 F0 8D 45 E4 50 8D 45 F8 66 0F 13 }"}
{"name":"$a2","value":"{ 8B 06 81 38 46 49 44 45 75 ?? 81 78 04 4C 2E 43 41 74 }"}
{"name":"$b1","value":"\"We also inform that your databases, ftp server and file server were downloaded by us to our servers.\" ascii fullword"}
{"name":"$b2","value":"\"Good day. All your files are encrypted. For decryption contact us.\" ascii fullword"}
{"name":"$b3","value":"\".cuba\" wide fullword"}
Threat Analysis
This YARA rule is designed to detect general threats.
Severity Level: Critical
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 Windows_Ransomware_Cuba.yar /path/to/suspicious/file # Scan a directory recursively yara -r Windows_Ransomware_Cuba.yar /path/to/directory/ # Scan with metadata output yara -m Windows_Ransomware_Cuba.yar target_file # Scan process memory (Linux) yara Windows_Ransomware_Cuba.yar /proc/[pid]/exe
Integration Examples
Python (yara-python)
import yara
rules = yara.compile(filepath='Windows_Ransomware_Cuba.yar')
matches = rules.match('/path/to/file')
ClamAV Integration
clamscan --yara-rules=Windows_Ransomware_Cuba.yar /path/to/scan
Rule Information
YARA ID
YARA-2025-1299
Author
Unknown
Repository
Created
August 19, 2025
Last Updated
August 19, 2025
Last Imported
Never
Threat Intelligence
Risk Level
Critical
Category
general
Detection Confidence
Analysis Pending
False Positive Rate
Not Available
Last Seen in Wild
No Data
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