WannaCry Ransomware Worm Embedding Massive ZIP Resource Payload


Zero‑Dwell Threat Intelligence Report

A narrative, executive‑ready view into the malware’s behavior, exposure, and reliable defenses.
Generated: 2025-12-04 08:29:39 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
4ivs1hb.exe
Type
Win32 Executable MS Visual C++ (generic)
SHA‑1
b528ec2b8bc1fb287babd1898d494e6b070f385c
MD5
9c83930b70029785c898b9a741dbed87
First Seen
2025-12-02 11:33:19.510183
Last Analysis
2025-12-02 18:56:41.723439
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
2025-11-26 00:42:37 UTC First VirusTotal submission
2025-12-03 21:10:05 UTC Latest analysis snapshot 7 days, 20 hours, 27 minutes
2025-12-04 08:29:39 UTC Report generation time 8 days, 7 hours, 47 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: 68. Missed: 5. Coverage: 93.2%.

Detected Vendors

  • Xcitium
  • +67 additional vendors (names not provided)

List includes Xcitium plus an additional 67 vendors per the provided summary.

Missed Vendors

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

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.

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