user@threatcheck.sh ~ threat-analysis
bash
$ analyze-threat Virus:Win32/Expiro.EK!MTB
Virus:Win32/Expiro.EK!MTB - Windows Defender threat signature analysis

Virus:Win32/Expiro.EK!MTB - Windows Defender Threat Analysis

$ cat analysis.txt
=== THREAT ANALYSIS REPORT ===
Threat Name: Virus:Win32/Expiro.EK!MTB
Classification:
Type:Virus
Platform:Win32
Family:Expiro
Detection Type:Concrete
Known malware family with identified signatures
Variant:EK
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: Virus - Infects other files for 32-bit Windows platform, family Expiro

Summary:

Virus:Win32/Expiro.EK!MTB is a highly sophisticated polymorphic file infector detected through concrete signatures and machine learning behavioral analysis. It exhibits extensive capabilities including process injection/hooking, persistence via scheduled tasks and BITS jobs, and execution via legitimate Windows utilities like rundll32 and PowerShell. This threat aims for deep system compromise and sustained malicious activity.

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 Virus_Win32_Expiro_EK_2147899592_0
{
    meta:
        author = "threatcheck.sh"
        detection_name = "Virus:Win32/Expiro.EK!MTB"
        threat_id = "2147899592"
        type = "Virus"
        platform = "Win32: Windows 32-bit platform"
        family = "Expiro"
        severity = "Critical"
        info = "MTB: Microsoft Threat Behavior"
        signature_type = "SIGNATURE_TYPE_PEHSTR_EXT"
        threshold = "10"
        strings_accuracy = "High"
    strings:
        $x_5_1 = {55 53 0f 84 89 00 00 00 0f 85 83 00 00 00 00 00 00 00 53 56 68 02 01 00 00 0f 84 90 00 00 00 0f 85 8a 00 00 00 0f 84 35 e1 ff ff 0f 85 60 c4 ff ff e9 0f 84 6c 01 00 00 89 c6 89 e0 50 0f 84 f7 01 00 00 0f 85 f1 01 00 00 00 00 00 00 5d c2 04 00}  //weight: 5, accuracy: High
        $x_5_2 = {13 0f 84 41 01 00 00 0f 84 95 01 00 00 0f 85 8f 01 00 00 e9 0f 84 9e 00 00 00 47 3b 7c 1e 18 0f 82 70 01 00 00 0f 84 88 00 00 00 0f 85 82 00 00 00 00 00 00 00 57 56 83 ec 40 8b 44 24 54 8b 68 08 8b 38}  //weight: 5, accuracy: High
    condition:
        (filesize < 20MB) and
        (all of ($x*))
}
Known malware which is associated with this threat:
Filename: 2026Orden de Compra.exe
5167338e9391173e6017b1aa8a79bf23093f3673494199d6a92e5b77e0bd4aa2
27/01/2026
→VirusTotal↓Download Sample
Filename: Cotizacion del espacio culinario.exe
5c523a295e64ca123dda4f517b1c9ee609af1f33ad3d8879c0e56505141a81d9
24/01/2026
→VirusTotal↓Download Sample
Filename: Cotizacion.exe
7d430bdeccbced4e2edfaecf2854fc4a89b6002d8bcc63a0bfab14c0e03b1060
23/01/2026
→VirusTotal↓Download Sample
Filename: ORDEN DE COMPRA DE 21_2026.exe
2986b0bd4774daf7ffbfa4f6fd239a3842e98c5774ea14ebf4726a4f8fca2a30
22/01/2026
→VirusTotal↓Download Sample
Filename: EWWO1 SO25-00223.exe
768a6767c853674899b69ac9a73f4f613d91c28ec414720baf65136569d654a3
13/01/2026
→VirusTotal↓Download Sample
Remediation Steps:
Immediately isolate the affected system(s) to prevent further spread. Conduct a full system scan with updated antivirus/EDR, remove all detected malicious files, and meticulously check for and remove any established persistence mechanisms (e.g., scheduled tasks, registry entries, BITS jobs). If complete eradication cannot be confirmed, re-image the system(s).
=== END REPORT ===
$ reanalyze-threat
This analysis was last updated on 10/12/2025. Do you want to analyze it again?
$ ls available-commands/
→ cd /home
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