Downloader Trojan (Upatre/Baoc) Fetching Ransomware via HTTP C2


Zero‑Dwell Threat Intelligence Report

A narrative, executive‑ready view into the malware’s behavior, exposure, and reliable defenses.
Generated: 2025-11-14 22:22:04 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
gewos.exe
Type
PE32 executable (GUI) Intel 80386, for MS Windows
SHA‑1
983892471add8d9c8841327aa9460a7ef1862f88
MD5
79e4c09abbbc6e79b500160b753c75d2
First Seen
2025-10-06 05:59:43.655634
Last Analysis
2025-10-06 07:50:35.504708
Dwell Time
0 days, 7 hours, 33 minutes

Extended Dwell Time Impact

For 1+ hours, this malware remained undetected — a limited but sufficient window for the adversary to complete initial execution and establish basic system access.

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
2025-10-05 14:53:43 UTC First VirusTotal submission
2025-10-08 14:27:48 UTC Latest analysis snapshot 2 days, 23 hours, 34 minutes
2025-11-14 22:22:04 UTC Report generation time 30 days, 16 hours, 28 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: 69. Missed: 4. Coverage: 94.5%.

Detected Vendors

  • Xcitium
  • +68 additional vendors (names not provided)

List includes Xcitium plus an additional 68 vendors per the provided summary.

Missed Vendors

  • Acronis
  • CMC
  • TACHYON
  • TrendMicro

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 (53.30% 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 744 53.30%
File System 272 19.48%
Registry 269 19.27%
Process 47 3.37%
Device 22 1.58%
Windows 13 0.93%
Misc 10 0.72%
Synchronization 8 0.57%
Com 6 0.43%
Threading 4 0.29%
Hooking 1 0.07%

MITRE ATT&CK Mapping

  • T1564.003 – hide graphical window
  • T1059 – accept command line arguments
  • T1547.001 – reference startup folder
  • T1027 – encrypt data using RC4 PRGA

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.aieov.com 76.223.54.146 United States Amazon.com, Inc.
www.msftncsi.com 23.32.45.134 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
www.aieov.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 30 udp
3702 1 udp

UDP Packets

Source IP Dest IP Sport Dport Time Proto
192.168.56.11 192.168.56.255 137 137 3.2442469596862793 udp
192.168.56.11 224.0.0.252 49563 5355 3.173179864883423 udp
192.168.56.11 224.0.0.252 54650 5355 3.1755709648132324 udp
192.168.56.11 224.0.0.252 55601 5355 4.120916843414307 udp
192.168.56.11 224.0.0.252 60205 5355 3.1836068630218506 udp
192.168.56.11 224.0.0.252 62798 5355 5.744611978530884 udp
192.168.56.11 239.255.255.250 62184 3702 3.181121826171875 udp
192.168.56.11 8.8.4.4 51628 53 113.10334777832031 udp
192.168.56.11 8.8.4.4 51663 53 174.65094685554504 udp
192.168.56.11 8.8.4.4 51690 53 6.9631829261779785 udp
192.168.56.11 8.8.4.4 51880 53 207.36970686912537 udp
192.168.56.11 8.8.4.4 51899 53 5.8848888874053955 udp
192.168.56.11 8.8.4.4 56213 53 36.806503772735596 udp
192.168.56.11 8.8.4.4 56473 53 98.71319890022278 udp
192.168.56.11 8.8.4.4 58917 53 80.36922597885132 udp
192.168.56.11 8.8.4.4 59770 53 51.52568197250366 udp
192.168.56.11 8.8.4.4 60334 53 127.5257019996643 udp
192.168.56.11 8.8.4.4 61507 53 145.8378918170929 udp
192.168.56.11 8.8.4.4 62120 53 160.21337485313416 udp
192.168.56.11 8.8.4.4 62329 53 65.91639685630798 udp
192.168.56.11 8.8.4.4 63439 53 22.416536808013916 udp
192.168.56.11 8.8.4.4 63550 53 192.97899198532104 udp
192.168.56.11 8.8.8.8 51628 53 112.1040518283844 udp
192.168.56.11 8.8.8.8 51663 53 173.65091681480408 udp
192.168.56.11 8.8.8.8 51690 53 7.962739944458008 udp
192.168.56.11 8.8.8.8 51880 53 206.36944198608398 udp
192.168.56.11 8.8.8.8 51899 53 6.884900808334351 udp
192.168.56.11 8.8.8.8 56213 53 35.80742788314819 udp
192.168.56.11 8.8.8.8 56473 53 97.71347093582153 udp
192.168.56.11 8.8.8.8 58917 53 79.36965680122375 udp
192.168.56.11 8.8.8.8 59770 53 50.52554392814636 udp
192.168.56.11 8.8.8.8 60334 53 126.52572298049927 udp
192.168.56.11 8.8.8.8 61507 53 144.8384428024292 udp
192.168.56.11 8.8.8.8 62120 53 159.21382093429565 udp
192.168.56.11 8.8.8.8 62329 53 64.91639280319214 udp
192.168.56.11 8.8.8.8 63439 53 21.416367769241333 udp
192.168.56.11 8.8.8.8 63550 53 191.97900199890137 udp

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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