WannaCry-Themed Trojan Executable Exhibiting Classic Filecoder Behavior


Zero‑Dwell Threat Intelligence Report

A narrative, executive‑ready view into the malware’s behavior, exposure, and reliable defenses.
Generated: 2025-12-04 08:32:41 UTC

Executive Overview — What We’re Dealing With

This specimen has persisted long enough to matter. Human experts classified it as Malware, and the telemetry confirms a capable, evasive Trojan with real impact potential.

File
6etrjn8.exe
Type
Microsoft Visual C++ compiled executable (generic)
SHA‑1
d302af9e0d3279238ee9f37bfec21f1774cb1db2
MD5
2386aadb11875d78487f3f068eafa693
First Seen
2025-12-01 14:09:03.336112
Last Analysis
2025-12-01 21:28:47.857034
Dwell Time
0 days, 7 hours, 33 minutes

Extended Dwell Time Impact

For 7+ hours, this malware remained undetected — a several-hour window that allowed the adversary to complete initial compromise and begin early-stage persistence establishment.

Comparative Context

Industry studies report a median dwell time closer to 21–24 days. This case represents rapid detection and containment within hours rather than days.

Timeline

Time (UTC) Event Elapsed
2025-11-29 18:07:26 UTC First VirusTotal submission
2025-12-03 21:12:19 UTC Latest analysis snapshot 4 days, 3 hours, 4 minutes
2025-12-04 08:32:41 UTC Report generation time 4 days, 14 hours, 25 minutes

Why It Matters

Every additional day of dwell time is not just an abstract number — it is attacker opportunity. Each day equates to more time for lateral movement, stealth persistence, and intelligence gathering.

Global Detection Posture — Who Caught It, Who Missed It

VirusTotal engines: 72. Detected as malicious: 58. Missed: 14. Coverage: 80.6%.

Detected Vendors

  • Xcitium
  • +57 additional vendors (names not provided)

List includes Xcitium plus an additional 57 vendors per the provided summary.

Missed Vendors

  • Acronis
  • Baidu
  • ClamAV
  • CMC
  • Kaspersky
  • MaxSecure
  • SentinelOne
  • TACHYON
  • tehtris
  • Trapmine
  • TrendMicro
  • ViRobot
  • Zillya
  • ZoneAlarm

Why it matters: if any endpoint relies solely on a missed engine, this malware can operate with zero alerts. Prevention‑first controls close that gap regardless of signature lag.

Behavioral Storyline — How the Malware Operates

Dominant system-level operations (71.43% of behavior) suggest this malware performs deep system reconnaissance, privilege escalation, or core OS manipulation. It’s actively probing system defenses and attempting to gain administrative control.

Behavior Categories (weighted)

Weight values represent the frequency and intensity of malware interactions with specific system components. Higher weights indicate more aggressive targeting of that category. Each operation (registry access, file modification, network connection, etc.) contributes to the category’s total weight, providing a quantitative measure of the malware’s behavioral focus.

Category Weight Percentage
System 10 71.43%
Process 2 14.29%
Registry 2 14.29%

MITRE ATT&CK Mapping

  • T1129 – link many functions at runtime
  • T1129 – link function at runtime on Windows

Following the Trail — Network & DNS Activity

Outbound activity leans on reputable infrastructure (e.g., CDNs, cloud endpoints) to blend in. TLS sessions and
HTTP calls show routine beaconing and IP‑lookup behavior that can masquerade as normal browsing.

Observed IPs

IP Country ASN/Org
224.0.0.252
8.8.4.4 United States Google LLC
8.8.8.8 United States Google LLC

DNS Queries

Request Type
5isohu.com A

Contacted IPs

IP Country ASN/Org
224.0.0.252
8.8.4.4 United States Google LLC
8.8.8.8 United States Google LLC

Port Distribution

Port Count Protocols
137 1 udp
5355 4 udp
53 2 udp

UDP Packets

Source IP Dest IP Sport Dport Time Proto
192.168.56.14 192.168.56.255 137 137 3.0786330699920654 udp
192.168.56.14 224.0.0.252 51209 5355 3.0120911598205566 udp
192.168.56.14 224.0.0.252 53401 5355 4.0767600536346436 udp
192.168.56.14 224.0.0.252 55094 5355 5.6256492137908936 udp
192.168.56.14 224.0.0.252 55848 5355 3.01249098777771 udp
192.168.56.14 8.8.4.4 52815 53 7.093865156173706 udp
192.168.56.14 8.8.8.8 52815 53 8.094098091125488 udp

Hunting tip: alert on unknown binaries initiating TLS to IP‑lookup services or unusual CDN endpoints — especially early in execution.

Persistence & Policy — Registry and Services

Registry and service telemetry points to policy awareness and environment reconnaissance rather than noisy persistence. Below is a compact view of the most relevant keys and handles; expand to see the full lists where available.

Registry Opened

3

Registry Set

0

Services Started

0

Services Opened

0

Registry Opened (Top 25)

Key
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\GRE_Initialize
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\GRE_Initialize\DisableUmpdBufferSizeCheck
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\GRE_Initialize\DisableMetaFiles
Show all (3 total)

Registry Set (Top 25)

Services Started (Top 15)

Services Opened (Top 15)

What To Do Now — Practical Defense Playbook

  • Contain unknowns: block first‑run binaries by default — signatures catch up, containment works now.
  • EDR controls: alert on keyboard hooks, screen capture APIs, VM/sandbox checks, and command‑shell launches.
  • Registry watch: flag queries/sets under policy paths (e.g., …\FipsAlgorithmPolicy\*).
  • Network rules: inspect outbound TLS to IP‑lookup services and unexpected CDN endpoints.
  • Hunt broadly: sweep endpoints for the indicators above and quarantine positives immediately.

Dwell time equals attacker opportunity. Reducing execution privileges and egress shrinks that window even when vendors disagree.

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