user@threatcheck.sh ~ threat-analysis
bash
$ analyze-threat Ransom:Win32/StopCrypt.MGK!MTB
Ransom:Win32/StopCrypt.MGK!MTB - Windows Defender threat signature analysis

Ransom:Win32/StopCrypt.MGK!MTB - Windows Defender Threat Analysis

$ cat analysis.txt
=== THREAT ANALYSIS REPORT ===
Threat Name: Ransom:Win32/StopCrypt.MGK!MTB
Classification:
Type:Ransom
Platform:Win32
Family:StopCrypt
Detection Type:Concrete
Known malware family with identified signatures
Variant:MGK
Specific signature variant within the malware family
Suffix:!MTB
Detected via machine learning and behavioral analysis
Detection Method:Behavioral
Confidence:Very High
False-Positive Risk:Low

Concrete signature match: Ransomware - Encrypts files and demands payment for 32-bit Windows platform, family StopCrypt

Summary:

This is a concrete detection of Ransom:Win32/StopCrypt.MGK!MTB, a highly malicious ransomware variant. It utilizes advanced techniques like process hooking, abuse of Windows utilities (e.g., rundll32, PowerShell, scheduled tasks, BITS), and file deletion to encrypt user data and establish persistence.

Severity:
Critical
VDM Static Detection:
Relevant strings associated with this threat:
 - !#HSTR:StringCodeForMshta.A!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForHooking.C!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForHooking.D!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForHooking.L!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForHooking.O!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForRegsvr32.A!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForRundll32.A!pli (PEHSTR_EXT)
 - rundll32 (PEHSTR_EXT)
 - !#HSTR:StringCodeForBITSJobs.A!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForPowerShell.G!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForScheduledTask.A!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForDataEncoding.D!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForHooking.J!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForHooking.K!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForRemoteFileCopy.B!pli (PEHSTR_EXT)
 - !#HSTR:ExecutionGuardrails (PEHSTR_EXT)
 - !#HSTR:StringCodeForFileDeletion.A!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForHooking.M!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForNetshHelperDLL.A!pli (PEHSTR_EXT)
 - !#HSTR:StringCodeForRemoteServices.A!pli (PEHSTR_EXT)
YARA Rule:
rule Ransom_Win32_StopCrypt_MGK_2147794300_0
{
    meta:
        author = "threatcheck.sh"
        detection_name = "Ransom:Win32/StopCrypt.MGK!MTB"
        threat_id = "2147794300"
        type = "Ransom"
        platform = "Win32: Windows 32-bit platform"
        family = "StopCrypt"
        severity = "Critical"
        info = "MTB: Microsoft Threat Behavior"
        signature_type = "SIGNATURE_TYPE_PEHSTR_EXT"
        threshold = "1"
        strings_accuracy = "High"
    strings:
        $x_1_1 = {55 8b ec 8b 45 08 8b 4d 0c 33 08 8b 55 08 89 0a 5d c2}  //weight: 1, accuracy: High
        $x_1_2 = {55 8b ec 8b 45 08 8b 08 33 4d 0c 8b 55 08 89 0a 5d c2}  //weight: 1, accuracy: High
    condition:
        (filesize < 20MB) and
        (1 of ($x*))
}
Known malware which is associated with this threat:
Filename: njb79h.exe
269d2ae2661789f8929d934a7f7e44b6d6fa2e2fc3799fd53b44988aed906b1f
07/12/2025
→VirusTotal↓Download Sample
Remediation Steps:
Immediately isolate the affected system, remove all detected malicious files, and restore data from verified clean backups. Conduct a thorough forensic analysis, update security definitions, patch all vulnerabilities, and implement strong endpoint protection and incident response protocols.
=== END REPORT ===
$ reanalyze-threat
This analysis was last updated on 07/12/2025. Do you want to analyze it again?
$ ls available-commands/
→ cd /home
user@threatcheck.sh:~$ ▊