Static Go Ransomware Leveraging Thread Context Rewriting and Waitable Timers

  • February 25, 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: 2026-02-25 17:37:38 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
3nxx0u.exe
Type
Win64 Executable (generic)
SHA‑1
b13609d5ea2a951ff6ae92cb1e273d9db345b94d
MD5
204ac9405649fbcc525bd50f962b7b29
First Seen
2026-02-18 11:11:36.538148
Last Analysis
2026-02-25 15:20:28.623912
Dwell Time
0 days, 7 hours, 33 minutes

Extended Dwell Time Impact

For 7+ days, this malware remained undetected — providing the adversary meaningful time to establish persistence mechanisms, perform system reconnaissance, escalate privileges, and begin data harvesting operations.

Comparative Context

Industry studies report a median dwell time closer to 21–24 days. While this case is below that median, any multi-day dwell time represents meaningful attacker opportunity.

Timeline

Time (UTC) Event Elapsed
2025-12-08 22:17:53 UTC First VirusTotal submission
2026-02-23 14:41:36 UTC Latest analysis snapshot 76 days, 16 hours, 23 minutes
2026-02-25 17:37:38 UTC Report generation time 78 days, 19 hours, 19 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
  • APEX
  • Avira
  • Baidu
  • Bkav
  • CAT-QuickHeal
  • ClamAV
  • CMC
  • F-Secure
  • google_safebrowsing
  • Gridinsoft
  • Ikarus
  • Jiangmin
  • NANO-Antivirus
  • Panda
  • Sangfor
  • SentinelOne
  • Skyhigh
  • SUPERAntiSpyware
  • TACHYON
  • tehtris
  • Trapmine
  • VBA32
  • VirIT
  • ViRobot
  • Webroot
  • Yandex
  • 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.

Behavioral Storyline — How the Malware Operates

Dominant system-level operations (72.22% 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 13 72.22%
Process 2 11.11%
Registry 2 11.11%
File System 1 5.56%

MITRE ATT&CK Mapping

  • T1027 – encode data using XOR
  • T1129 – access PEB ldr_data
  • T1027 – encrypt data using Salsa20 or ChaCha
  • T1027 – reference AES constants
  • T1027 – encrypt data using RC4 PRGA
  • T1027 – encrypt data using AES via x86 extensions
  • T1027 – encrypt data using AES
  • T1129 – get kernel32 base address
  • T1027 – encode data using Base64
  • T1140 – decrypt data using AES via x86 extensions
  • T1027 – reference Base64 string
  • 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
  • T1486 – Exhibits possible ransomware or wiper file modification behavior: overwrites_existing_files
  • T1036 – Creates files inside the user directory
  • T1027.002 – PE file has section (not .text) which is very likely to contain packed code (zlib compression ratio < 0.011)
  • T1082 – Queries the volume information (name, serial number etc) of a device
  • 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.

Contacted Domains

Domain IP Country ASN/Org
www.msftncsi.com 23.200.3.18 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
www.msftncsi.com A
5isohu.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
138 1 udp
5355 5 udp
53 4 udp
3702 1 udp

UDP Packets

Source IP Dest IP Sport Dport Time Proto
192.168.56.11 192.168.56.255 137 137 3.243259906768799 udp
192.168.56.11 192.168.56.255 138 138 9.258677959442139 udp
192.168.56.11 224.0.0.252 49563 5355 3.172590970993042 udp
192.168.56.11 224.0.0.252 54650 5355 3.1775808334350586 udp
192.168.56.11 224.0.0.252 55601 5355 4.685054779052734 udp
192.168.56.11 224.0.0.252 60205 5355 3.1841368675231934 udp
192.168.56.11 224.0.0.252 62798 5355 5.758579969406128 udp
192.168.56.11 239.255.255.250 62184 3702 3.1814827919006348 udp
192.168.56.11 8.8.4.4 51690 53 7.5246148109436035 udp
192.168.56.11 8.8.4.4 51899 53 5.899292945861816 udp
192.168.56.11 8.8.8.8 51690 53 8.524345874786377 udp
192.168.56.11 8.8.8.8 51899 53 6.899336814880371 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

21

Registry Set

7

Services Started

0

Services Opened

0

Registry Opened (Top 25)

Key
HKEY_LOCAL_MACHINE\Software\Classes\CLSID\{4336A54D-038B-4685-AB02-99BB52D3FB8B}\Instance\
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\CloudStore
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\CloudStore\Store\Cache\DefaultAccount\$de${a24c164a-dcf8-4844-af66-4dd3ddac01d9}$start.tilegrid$windows.data.curatedtilecollection.tilecollection\Current
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\SessionInfo\1\ApplicationViewManagement\W32:0000000000050028
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Search\JumplistData
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Search
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\Desktop\NameSpace\DelegateFolders\
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\SessionInfo\1\ApplicationViewManagement\W32:00000000000F02B4
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
HKEY_LOCAL_MACHINE\Software\Microsoft\LanguageOverlay\OverlayPackages\en-US
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\SdbUpdates
HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Safer\CodeIdentifiers
HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\MUI\Settings
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\AppModel\Lookaside\user
HKEY_LOCAL_MACHINE\OSDATA\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Segment Heap
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\SdbUpdates\ManifestedMergeStubSdbs
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Policies\Microsoft\Cryptography\Configuration
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\AppModel\Lookaside\machine
Show all (21 total)

Registry Set (Top 25)

Key Value
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\bam\State\UserSettings\S-1-5-21-4226853953-3309226944-3078887307-1000\%WINDIR%\System32\WindowsPowerShell\v1.0\powershell.exe \x9c\x01\xbd\xa9\x7f\x69\xdc\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\SessionInfo\1\ApplicationViewManagement\W32:0000000000050028\VirtualDesktop \x10\x00\x00\x00\x30\x30\x44\x56\xa6\xeb\x51\xa7\xc8\xad\xf8\x4f\xae\x21\x3c\xfc\xfc\xea\x91\x10
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Search\JumplistData\{1AC14E77-02E7-4E5D-B744-2EB1AE5198B7}\WindowsPowerShell\v1.0\powershell.exe REG_QWORD
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\SessionInfo\1\ApplicationViewManagement\W32:00000000000F02B4\VirtualDesktop \x10\x00\x00\x00\x30\x30\x44\x56\xa6\xeb\x51\xa7\xc8\xad\xf8\x4f\xae\x21\x3c\xfc\xfc\xea\x91\x10
HKEY_CURRENT_USER\Software\Microsoft\Windows\Shell\Bags\1\Desktop\IconLayouts \x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x03\x00\x01\x00\x01\x00\x01\x00\x1c\x00\x00\x00\x00\x00\x00\x00\x2c\x00\x00\x00\x00\x00\x00\x00\x3a\x00\x3a\x00\x7b\x00\x36\x00\x34\x00\x35\x00\x46\x00\x46\x00\x30\x00\x34\x00\x30\x00\x2d\x00\x35\x00\x30\x00\x38\x00\x31\x00\x2d\x00\x31\x00\x30\x00\x31\x00\x42\x00\x2d\x00\x39…
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Search\InstalledWin32AppsRevision {E1E41C38-C539-4FFA-9662-D0A875C58A91}
HKEY_CURRENT_USER\Software\Microsoft\Windows\Shell\Bags\1\Desktop\IconNameVersion 0x00000001

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.