locdoor_ransomware
YARA-2025-0823
Critical
general
Active
Rule to detect Locdoor/DryCry
locdoor_ransomware.yar
Valid Syntax
rule locdoor_ransomware {
meta:
description = "Rule to detect Locdoor/DryCry"
author = "Marc Rivero | @seifreed"
reference = "https://twitter.com/leotpsc/status/1036180615744376832"
strings:
$s1 = "copy \"Locdoor.exe\" \"C:\\ProgramData\\Microsoft\\Windows\\Start Menu\\Programs\\StartUp\\temp00000000.exe\"" fullword ascii
$s2 = "copy wscript.vbs C:\\ProgramData\\Microsoft\\Windows\\Start Menu\\Programs\\StartUp\\wscript.vbs" fullword ascii
$s3 = "!! Your computer's important files have been encrypted! Your computer's important files have been encrypted!" fullword ascii
$s4 = "echo CreateObject(\"SAPI.SpVoice\").Speak \"Your computer's important files have been encrypted! " fullword ascii
$s5 = "! Your computer's important files have been encrypted! " fullword ascii
$s7 = "This program is not supported on your operating system." fullword ascii
$s8 = "echo Your computer's files have been encrypted to Locdoor Ransomware! To make a recovery go to localbitcoins.com and create a wa" ascii
$s9 = "Please enter the password." fullword ascii
condition:
( uint16(0) == 0x5a4d and filesize < 600KB ) and all of them
}
Rule Metadata
description
Rule to detect Locdoor/DryCry
author
Marc Rivero | @seifreed
reference
https://twitter.com/leotpsc/status/1036180615744376832
String Definitions
{"name":"$s1","value":"\"copy \\\"Locdoor.exe\\\" \\\"C:\\\\ProgramData\\\\Microsoft\\\\Windows\\\\Start Menu\\\\Programs\\\\StartUp\\\\temp00000000.exe\\\"\" fullword ascii"}
{"name":"$s2","value":"\"copy wscript.vbs C:\\\\ProgramData\\\\Microsoft\\\\Windows\\\\Start Menu\\\\Programs\\\\StartUp\\\\wscript.vbs\" fullword ascii"}
{"name":"$s3","value":"\"!! Your computer's important files have been encrypted! Your computer's important files have been encrypted!\" fullword ascii"}
{"name":"$s4","value":"\"echo CreateObject(\\\"SAPI.SpVoice\\\").Speak \\\"Your computer's important files have been encrypted! \" fullword ascii"}
{"name":"$s5","value":"\"! Your computer's important files have been encrypted! \" fullword ascii"}
{"name":"$s7","value":"\"This program is not supported on your operating system.\" fullword ascii"}
{"name":"$s8","value":"\"echo Your computer's files have been encrypted to Locdoor Ransomware! To make a recovery go to localbitcoins.com and create a wa\" ascii"}
{"name":"$s9","value":"\"Please enter the password.\" fullword ascii"}
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 locdoor_ransomware.yar /path/to/suspicious/file # Scan a directory recursively yara -r locdoor_ransomware.yar /path/to/directory/ # Scan with metadata output yara -m locdoor_ransomware.yar target_file # Scan process memory (Linux) yara locdoor_ransomware.yar /proc/[pid]/exe
Integration Examples
Python (yara-python)
import yara
rules = yara.compile(filepath='locdoor_ransomware.yar')
matches = rules.match('/path/to/file')
ClamAV Integration
clamscan --yara-rules=locdoor_ransomware.yar /path/to/scan
Rule Information
YARA ID
YARA-2025-0823
Author
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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