Microsoft-Signed Certificate Abuse Aligns with MuddyWater Malware Operations

  • May 8, 2026
Share with your community:


Zero‑Dwell Threat Intelligence Report

A narrative, executive‑ready view into the malware’s behavior, exposure, and reliable defenses.
Generated: 2026-05-08 14:16:54 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
blammchy5.exe
Type
Win64 Executable (generic)
SHA‑1
4a54b7237dc9fdd745d0d19083a1ce4857c91de4
MD5
f8560b9a893eeb2130fc7159e9c1b851
First Seen
2026-05-08 13:12:42.172620
Last Analysis
2026-05-08 13:20:54.091023
Dwell Time
0 days, 7 hours, 33 minutes

Extended Dwell Time Impact

For 8+ minutes, this malware was rapidly detected — demonstrating excellent security controls that intercepted the threat during initial execution phases, severely limiting adversary capabilities.

Comparative Context

Industry studies report a median dwell time closer to 21–24 days. This case represents extremely rapid detection within minutes.

Timeline

Time (UTC) Event Elapsed
2026-02-19 09:43:05 UTC First VirusTotal submission
2026-05-08 13:52:25 UTC Latest analysis snapshot 78 days, 4 hours, 9 minutes
2026-05-08 14:16:54 UTC Report generation time 78 days, 4 hours, 33 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: 44. Missed: 28. Coverage: 61.1%.

Detected Vendors

  • Xcitium
  • +43 additional vendors (names not provided)

List includes Xcitium plus an additional 43 vendors per the provided summary.

Missed Vendors

  • Acronis
  • Alibaba
  • APEX
  • Avira
  • Bkav
  • ClamAV
  • CMC
  • Cylance
  • Cynet
  • Elastic
  • google_safebrowsing
  • Gridinsoft
  • huorong
  • Jiangmin
  • Kingsoft
  • NANO-Antivirus
  • Sangfor
  • SentinelOne
  • SUPERAntiSpyware
  • TACHYON
  • tehtris
  • Trapmine
  • VirIT
  • Webroot
  • Xcitium
  • Zillya
  • ZoneAlarm
  • Zoner

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

  • T1082 – get hostname
  • T1027 – encrypt or decrypt data via BCrypt
  • T1140 – decode data using Base64 via WinAPI
  • T1027 – encrypt data using RC4 PRGA
  • T1083 – get common file path
  • T1083 – check if file exists
  • T1056.001 – log keystrokes via polling
  • T1033 – get token membership
  • T1129 – link many functions at runtime
  • T1027 – encode data using XOR
  • T1027 – encode data using Base64 via WinAPI
  • T1564.003 – hide graphical window
  • T1083 – enumerate files on Windows
  • T1059.003 – execute shell command and capture output
  • T1033 – get session user name
  • T1087 – get session user name
  • T1059 – accept command line arguments
  • T1129 – link function at runtime on Windows
  • T1614 – get geographical location
  • T1129 – parse PE header
  • T1082 – query environment variable
  • T1071 – The PE file contains a suspicious PDB path
  • T1055 – Contains .tls (Thread Local Storage) section
  • T1027 – The binary contains an unknown PE section name indicative of packing
  • T1027.002 – The binary contains an unknown PE section name indicative of packing
  • T1059 – Apparent Internal Usage of CMD.EXE
  • T1063 – It Tries to detect injection methods

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.

Contacted Domains

Domain IP Country ASN/Org
www.msftncsi.com 23.219.36.108 United States Akamai Technologies, Inc.

Observed IPs

IP Country ASN/Org
224.0.0.252
239.255.255.250
8.8.4.4 United States Google LLC
8.8.8.8 United States Google LLC

DNS Queries

Request Type
5isohu.com A
www.msftncsi.com A

Contacted IPs

IP Country ASN/Org
224.0.0.252
239.255.255.250
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 5 udp
53 4 udp
3702 1 udp

UDP Packets

Source IP Dest IP Sport Dport Time Proto
192.168.56.13 192.168.56.255 137 137 3.244475841522217 udp
192.168.56.13 224.0.0.252 49311 5355 5.731182813644409 udp
192.168.56.13 224.0.0.252 55150 5355 3.172928810119629 udp
192.168.56.13 224.0.0.252 60010 5355 5.18413782119751 udp
192.168.56.13 224.0.0.252 62406 5355 3.177564859390259 udp
192.168.56.13 224.0.0.252 63527 5355 4.110294818878174 udp
192.168.56.13 239.255.255.250 52252 3702 3.1807730197906494 udp
192.168.56.13 8.8.4.4 54879 53 7.744459867477417 udp
192.168.56.13 8.8.4.4 54881 53 6.68939995765686 udp
192.168.56.13 8.8.8.8 54879 53 8.743875980377197 udp
192.168.56.13 8.8.8.8 54881 53 7.681374788284302 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

9

Registry Set

0

Services Started

0

Services Opened

0

Registry Opened (Top 25)

Key
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager
HKEY_LOCAL_MACHINE\OSDATA\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\SdbUpdates\ManifestedMergeStubSdbs
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\SdbUpdates
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Segment Heap
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\SideBySide\AssemblyStorageRoots
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags
HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Safer\CodeIdentifiers
Show all (9 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.

Like what you see? Share with a friend.