user@threatcheck.sh ~ threat-analysis
bash
$ analyze-threat Trojan:Win32/DarkCloud!rfn
Trojan:Win32/DarkCloud!rfn - Windows Defender threat signature analysis

Trojan:Win32/DarkCloud!rfn - Windows Defender Threat Analysis

$ cat analysis.txt
=== THREAT ANALYSIS REPORT ===
Threat Name: Trojan:Win32/DarkCloud!rfn
Classification:
Type:Trojan
Platform:Win32
Family:DarkCloud
Detection Type:Concrete
Known malware family with identified signatures
Suffix:!rfn
Specific ransomware family name
Confidence:Very High
False-Positive Risk:Low

Concrete signature match: Trojan - Appears legitimate but performs malicious actions for 32-bit Windows platform, family DarkCloud

Summary:

This is a confirmed trojan from the DarkCloud family that uses multiple legitimate Windows tools ('Living-off-the-Land') like PowerShell, mshta, and rundll32 to execute malicious code. It establishes persistence via scheduled tasks, hooks system functions to evade detection, and is capable of downloading additional payloads or exfiltrating data.

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)
No specific strings found for this threat
YARA Rule:
rule Trojan_Win64_DarkCloud_DB_2147942806_0
{
    meta:
        author = "threatcheck.sh"
        detection_name = "Trojan:Win64/DarkCloud.DB!MTB"
        threat_id = "2147942806"
        type = "Trojan"
        platform = "Win64: Windows 64-bit platform"
        family = "DarkCloud"
        severity = "Critical"
        info = "MTB: Microsoft Threat Behavior"
        signature_type = "SIGNATURE_TYPE_PEHSTR_EXT"
        threshold = "1"
        strings_accuracy = "Low"
    strings:
        $x_1_1 = {0f b6 04 01 43 0f b6 0c 01 01 c1 0f b6 c1 48 8b 4d b0 8a 04 01 48 63 4d f4 41 30 04 0a 8b 45 f4 83 c0 01 89 45 e0 8b 05 ?? ?? ?? ?? 8d 48 ff 0f af c8 f6 c1 01 b8 ?? ?? ?? ?? b9 ?? ?? ?? ?? e9}  //weight: 1, accuracy: Low
    condition:
        (filesize < 20MB) and
        (all of ($x*))
}
Known malware which is associated with this threat:
ab28803f79757760027a140b87cf9d068ec8c6c8ebc541a680b6f874aeb63a05
07/11/2025
→VirusTotal↓Download Sample
Remediation Steps:
Immediately isolate the host from the network. Use Windows Defender to remove the threat, then perform a full system scan. Manually inspect for and remove suspicious scheduled tasks or other persistence mechanisms. Change all passwords for accounts used on this machine.
=== END REPORT ===
$ reanalyze-threat
This analysis was last updated on 08/11/2025. Do you want to analyze it again?
$ ls available-commands/
→ cd /home
user@threatcheck.sh:~$ ▊