Win32 Upatre/Zbot Downloader Beacons and Executes Crypto-Encryptor


Zero‑Dwell Threat Intelligence Report

A narrative, executive‑ready view into the malware’s behavior, exposure, and reliable defenses.
Generated: 2025-11-10 07:11:59 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
hasfj.exe
Type
PE32 executable (GUI) Intel 80386, for MS Windows
SHA‑1
fc7fa9b8b82f8f9b29a7d8136c8c71fd54a39bc9
MD5
7f9d54b08c9812f75e29d5be01563236
First Seen
2025-10-06 05:58:21.609531
Last Analysis
2025-10-06 07:50:35.656676
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
2025-10-06 00:08:41 UTC First VirusTotal submission
2025-10-08 14:28:22 UTC Latest analysis snapshot 2 days, 14 hours, 19 minutes
2025-11-10 07:11:59 UTC Report generation time 30 days, 7 hours, 3 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

  • Acronis
  • CMC
  • TACHYON
  • TrendMicro
  • Yandex

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 (46.79% 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 810 46.79%
File System 477 27.56%
Registry 269 15.54%
Process 111 6.41%
Device 22 1.27%
Windows 13 0.75%
Misc 10 0.58%
Synchronization 8 0.46%
Com 6 0.35%
Threading 4 0.23%
Hooking 1 0.06%

MITRE ATT&CK Mapping

  • T1564.003 – hide graphical window
  • T1027 – encrypt data using RC4 PRGA
  • T1059 – accept command line arguments

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 13.248.169.48 United States Amazon Technologies Inc.
www.msftncsi.com 23.200.3.27 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 29 udp
3702 1 udp

UDP Packets

Source IP Dest IP Sport Dport Time Proto
192.168.56.11 192.168.56.255 137 137 3.245469093322754 udp
192.168.56.11 224.0.0.252 49563 5355 3.173563003540039 udp
192.168.56.11 224.0.0.252 54650 5355 3.175967216491699 udp
192.168.56.11 224.0.0.252 55601 5355 4.218367099761963 udp
192.168.56.11 224.0.0.252 60205 5355 3.184237003326416 udp
192.168.56.11 224.0.0.252 62798 5355 5.760730028152466 udp
192.168.56.11 239.255.255.250 62184 3702 3.1816670894622803 udp
192.168.56.11 8.8.4.4 51628 53 113.07304811477661 udp
192.168.56.11 8.8.4.4 51663 53 174.69811511039734 udp
192.168.56.11 8.8.4.4 51690 53 7.042124032974243 udp
192.168.56.11 8.8.4.4 51899 53 5.901643991470337 udp
192.168.56.11 8.8.4.4 56213 53 36.85421013832092 udp
192.168.56.11 8.8.4.4 56473 53 98.69815516471863 udp
192.168.56.11 8.8.4.4 58917 53 80.38550305366516 udp
192.168.56.11 8.8.4.4 59770 53 51.556894063949585 udp
192.168.56.11 8.8.4.4 60334 53 127.51045203208923 udp
192.168.56.11 8.8.4.4 61507 53 145.83838605880737 udp
192.168.56.11 8.8.4.4 62120 53 160.26030802726746 udp
192.168.56.11 8.8.4.4 62329 53 65.94858312606812 udp
192.168.56.11 8.8.4.4 63439 53 22.479621171951294 udp
192.168.56.11 8.8.4.4 63550 53 193.04260301589966 udp
192.168.56.11 8.8.8.8 51628 53 112.073655128479 udp
192.168.56.11 8.8.8.8 51663 53 173.69848012924194 udp
192.168.56.11 8.8.8.8 51690 53 8.041715145111084 udp
192.168.56.11 8.8.8.8 51880 53 206.41706705093384 udp
192.168.56.11 8.8.8.8 51899 53 6.901026010513306 udp
192.168.56.11 8.8.8.8 56213 53 35.85412621498108 udp
192.168.56.11 8.8.8.8 56473 53 97.69853019714355 udp
192.168.56.11 8.8.8.8 58917 53 79.38567209243774 udp
192.168.56.11 8.8.8.8 59770 53 50.557844161987305 udp
192.168.56.11 8.8.8.8 60334 53 126.5110411643982 udp
192.168.56.11 8.8.8.8 61507 53 144.83899521827698 udp
192.168.56.11 8.8.8.8 62120 53 159.26115703582764 udp
192.168.56.11 8.8.8.8 62329 53 64.94859218597412 udp
192.168.56.11 8.8.8.8 63439 53 21.48008108139038 udp
192.168.56.11 8.8.8.8 63550 53 192.04245519638062 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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