WannaCry Ransomware Worm Compiled With Legacy Visual Studio Toolchain


Zero‑Dwell Threat Intelligence Report

A narrative, executive‑ready view into the malware’s behavior, exposure, and reliable defenses.
Generated: 2025-12-04 08:24:29 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
1a0h02ou.exe
Type
Win32 Executable MS Visual C++ (generic)
SHA‑1
28b5f8a9fd6ae5ef6e0b83f45f8cadbf9910bb83
MD5
b08ab1fbdfa27f53041c24ac3019f820
First Seen
2025-12-01 14:07:46.654183
Last Analysis
2025-12-01 21:28:46.652925
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
2025-11-14 10:42:35 UTC First VirusTotal submission
2025-12-03 21:10:43 UTC Latest analysis snapshot 19 days, 10 hours, 28 minutes
2025-12-04 08:24:29 UTC Report generation time 19 days, 21 hours, 41 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: 73. Detected as malicious: 67. Missed: 6. Coverage: 91.8%.

Detected Vendors

  • Xcitium
  • +66 additional vendors (names not provided)

List includes Xcitium plus an additional 66 vendors per the provided summary.

Missed Vendors

  • CMC
  • Google
  • google_safebrowsing
  • SUPERAntiSpyware
  • TACHYON
  • tehtris

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.

MITRE ATT&CK Mapping

  • T1129 – link function at runtime on Windows
  • T1083 – get common file path
  • T1543.003 – create service
  • T1569.002 – create service
  • T1129 – parse PE header
  • T1129 – link many functions at runtime
  • T1027 – reference AES constants
  • T1543.003 – start service
  • T1027 – encrypt data using AES
  • T1083 – check if file exists
  • T1222 – set file attributes
  • T1083 – get file size
  • T1027 – encode data using XOR
  • T1012 – query or enumerate registry value
  • T1082 – get hostname
  • T1543.003 – persist via Windows service
  • T1569.002 – persist via Windows service
  • T1027 – encrypt data using RC4 KSA

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.

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

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.

Scroll to Top