High-Severity Encoder Build Leveraging Waitable Timers and Vectored Exception Handling

  • February 19, 2026
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Zero‑Dwell Threat Intelligence Report

A narrative, executive‑ready view into the malware’s behavior, exposure, and reliable defenses.
Generated: 2026-02-19 10:34:53 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
jkx5s.exe
Type
Win64 Executable (generic)
SHA‑1
f5da096e2ae6079c4670ddd6566244618056a22e
MD5
94dd3315fca4c31ef61b7865c3b8983f
First Seen
2026-02-18 11:16:53.801211
Last Analysis
2026-02-19 08:54:27.538949
Dwell Time
0 days, 7 hours, 33 minutes

Extended Dwell Time Impact

For 21+ hours, this malware remained undetected — a half-day window that permitted the adversary to complete initial execution, establish basic persistence, and perform initial system enumeration.

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
2026-01-08 09:32:39 UTC First VirusTotal submission
2026-02-16 06:58:45 UTC Latest analysis snapshot 38 days, 21 hours, 26 minutes
2026-02-19 10:34:53 UTC Report generation time 42 days, 1 hours, 2 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: 49. Missed: 23. Coverage: 68.1%.

Detected Vendors

  • Xcitium
  • +48 additional vendors (names not provided)

List includes Xcitium plus an additional 48 vendors per the provided summary.

Missed Vendors

  • Acronis
  • APEX
  • Avira
  • Baidu
  • CMC
  • F-Secure
  • google_safebrowsing
  • Gridinsoft
  • Jiangmin
  • NANO-Antivirus
  • Sangfor
  • SentinelOne
  • Skyhigh
  • SUPERAntiSpyware
  • TACHYON
  • tehtris
  • Trapmine
  • ViRobot
  • Webroot
  • Xcitium
  • Yandex
  • 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

  • T1027 – encrypt data using AES via x86 extensions
  • T1027 – reference Base64 string
  • T1129 – get kernel32 base address
  • T1140 – decrypt data using AES via x86 extensions
  • T1027 – encode data using XOR
  • T1027 – encrypt data using Salsa20 or ChaCha
  • T1027 – encrypt data using RC4 PRGA
  • T1027 – reference AES constants
  • T1027 – encrypt data using AES
  • T1129 – access PEB ldr_data
  • T1027 – encode data using Base64
  • 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
  • T1045 – Manalize Local SandBox Packer Harvesting
  • T1082 – Queries the volume information (name, serial number etc) of a device
  • T1560 – Public key (encryption) found
  • T1090 – Found Tor onion address
  • T1486 – Writes a notice file (html or txt) to demand a ransom

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.

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

16

Registry Set

1

Services Started

0

Services Opened

0

Registry Opened (Top 25)

Key
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\GRE_Initialize\DisableMetaFiles
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\GRE_Initialize
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\GRE_Initialize\DisableUmpdBufferSizeCheck
HKEY_LOCAL_MACHINE\OSDATA\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\AppModel\Lookaside\user
HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\MUI\Settings
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Policies\Microsoft\Cryptography\Configuration
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\SdbUpdates\ManifestedMergeStubSdbs
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\AppModel\Lookaside\machine
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\SdbUpdates
HKEY_LOCAL_MACHINE\Software\Microsoft\LanguageOverlay\OverlayPackages\en-US
HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Safer\CodeIdentifiers
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Segment Heap
Show all (16 total)

Registry Set (Top 25)

Key Value
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\bam\State\UserSettings\S-1-5-21-4226853953-3309226944-3078887307-1000\C:\voqowxoi\rvqm.exe \xdd\x47\x23\x0b\xcb\x82\xdc\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00

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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