XWorm V5.6 RAT Uses Pastebin C2 and Packed Win64 Loader for Stealth Operations


Zero‑Dwell Threat Intelligence Report

A narrative, executive‑ready view into the malware’s behavior, exposure, and reliable defenses.
Generated: 2025-11-27 12:47:27 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
ywymltqck.exe
Type
Win64 Executable (generic)
SHA‑1
2df4f76eddd5d2cd1f2264b031bbbe5eeb183f50
MD5
473ce7ee51c4f978dcc21b9f935a560f
First Seen
2025-11-25 08:01:23.919993
Last Analysis
2025-11-25 09:02:43.655658
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
2025-11-24 19:56:06 UTC First VirusTotal submission
2025-11-27 07:00:42 UTC Latest analysis snapshot 2 days, 11 hours, 4 minutes
2025-11-27 12:47:27 UTC Report generation time 2 days, 16 hours, 51 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: 59. Missed: 14. Coverage: 80.8%.

Detected Vendors

  • Xcitium
  • +58 additional vendors (names not provided)

List includes Xcitium plus an additional 58 vendors per the provided summary.

Missed Vendors

  • Acronis
  • Alibaba
  • Antiy-AVL
  • Baidu
  • CMC
  • MaxSecure
  • NANO-Antivirus
  • SUPERAntiSpyware
  • TACHYON
  • tehtris
  • VBA32
  • 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.

Behavioral Storyline — How the Malware Operates

This threat shows heavy registry manipulation (55.82% of total behavior), indicating persistent backdoor installation, configuration tampering, or system policy modification attempts. The malware likely establishes persistence mechanisms and modifies security settings to maintain long-term access.

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
Registry 4417 55.82%
System 1942 24.54%
File System 702 8.87%
Process 405 5.12%
Network 158 2.00%
Misc 113 1.43%
Device 52 0.66%
Crypto 44 0.56%
Threading 36 0.45%
Synchronization 26 0.33%
Hooking 5 0.06%
Com 5 0.06%
Windows 4 0.05%
Services 4 0.05%

MITRE ATT&CK Mapping

  • T1083 – get file size
  • T1129 – link function at runtime on Windows
  • T1614 – get geographical location
  • T1083 – check if file exists
  • T1027 – encrypt data using RC4 PRGA
  • T1083 – get common file path
  • T1129 – parse PE header
  • T1027 – encode data using XOR
  • T1546.001 – persist via default file association registry key
  • T1222 – set file attributes
  • T1082 – get disk information
  • 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
pastebin.com 172.66.171.73 United States Cloudflare, Inc.
www.aieov.com 76.223.54.146 United States Amazon.com, Inc.
www.msftncsi.com 2.18.67.72 Europe Akamai Technologies

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
pastebin.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 6 udp
53 92 udp
3702 1 udp

UDP Packets

Source IP Dest IP Sport Dport Time Proto
192.168.56.13 192.168.56.255 137 137 3.244051933288574 udp
192.168.56.13 224.0.0.252 49311 5355 5.775382995605469 udp
192.168.56.13 224.0.0.252 55150 5355 3.1735730171203613 udp
192.168.56.13 224.0.0.252 58697 5355 15.058213949203491 udp
192.168.56.13 224.0.0.252 60010 5355 5.355648040771484 udp
192.168.56.13 224.0.0.252 62406 5355 3.175961971282959 udp
192.168.56.13 224.0.0.252 63527 5355 4.396138906478882 udp
192.168.56.13 239.255.255.250 52252 3702 3.1823298931121826 udp
192.168.56.13 8.8.4.4 50554 53 70.90042090415955 udp
192.168.56.13 8.8.4.4 52284 53 287.72808599472046 udp
192.168.56.13 8.8.4.4 52955 53 316.5565149784088 udp
192.168.56.13 8.8.4.4 53518 53 122.82178592681885 udp
192.168.56.13 8.8.4.4 53616 53 302.0874729156494 udp
192.168.56.13 8.8.4.4 53825 53 243.75939297676086 udp
192.168.56.13 8.8.4.4 53985 53 191.90053391456604 udp
192.168.56.13 8.8.4.4 54879 53 7.994734048843384 udp
192.168.56.13 8.8.4.4 54881 53 7.1971869468688965 udp
192.168.56.13 8.8.4.4 55460 53 330.8066439628601 udp
192.168.56.13 8.8.4.4 55551 53 88.1967658996582 udp
192.168.56.13 8.8.4.4 55743 53 175.30613589286804 udp
192.168.56.13 8.8.4.4 56086 53 160.7129909992218 udp
192.168.56.13 8.8.4.4 56197 53 80.90027189254761 udp
192.168.56.13 8.8.4.4 56202 53 226.47827696800232 udp
192.168.56.13 8.8.4.4 56770 53 269.4466278553009 udp
192.168.56.13 8.8.4.4 56908 53 193.58792400360107 udp
192.168.56.13 8.8.4.4 57065 53 128.05628395080566 udp
192.168.56.13 8.8.4.4 57310 53 36.16636896133423 udp
192.168.56.13 8.8.4.4 57415 53 37.10337495803833 udp
192.168.56.13 8.8.4.4 57885 53 330.13468194007874 udp
192.168.56.13 8.8.4.4 58070 53 207.96264505386353 udp
192.168.56.13 8.8.4.4 58554 53 312.88411498069763 udp
192.168.56.13 8.8.4.4 58920 53 51.900408029556274 udp
192.168.56.13 8.8.4.4 59610 53 146.3379180431366 udp
192.168.56.13 8.8.4.4 60389 53 261.05613589286804 udp
192.168.56.13 8.8.4.4 60543 53 113.63477301597595 udp
192.168.56.13 8.8.4.4 60780 53 157.35365295410156 udp
192.168.56.13 8.8.4.4 60910 53 53.55613589286804 udp
192.168.56.13 8.8.4.4 61004 53 99.25931286811829 udp
192.168.56.13 8.8.4.4 61279 53 359.6031539440155 udp
192.168.56.13 8.8.4.4 61800 53 174.6503188610077 udp
192.168.56.13 8.8.4.4 61897 53 222.3527979850769 udp
192.168.56.13 8.8.4.4 62422 53 209.18478298187256 udp
192.168.56.13 8.8.4.4 62491 53 278.30606484413147 udp
192.168.56.13 8.8.4.4 62493 53 22.64978003501892 udp
192.168.56.13 8.8.4.4 62729 53 345.24402689933777 udp
192.168.56.13 8.8.4.4 62849 53 17.8070330619812 udp
192.168.56.13 8.8.4.4 62980 53 240.6347620487213 udp
192.168.56.13 8.8.4.4 63240 53 347.4155468940735 udp
192.168.56.13 8.8.4.4 63617 53 364.6814639568329 udp
192.168.56.13 8.8.4.4 64533 53 105.55684089660645 udp
192.168.56.13 8.8.4.4 64642 53 295.5721869468689 udp
192.168.56.13 8.8.4.4 64700 53 255.0253119468689 udp
192.168.56.13 8.8.4.4 64801 53 66.32238101959229 udp
192.168.56.13 8.8.4.4 64886 53 140.07222700119019 udp
192.168.56.13 8.8.8.8 50554 53 69.90041494369507 udp
192.168.56.13 8.8.8.8 52284 53 286.73593187332153 udp
192.168.56.13 8.8.8.8 52955 53 315.566663980484 udp
192.168.56.13 8.8.8.8 53518 53 121.82535195350647 udp
192.168.56.13 8.8.8.8 53616 53 301.0915639400482 udp
192.168.56.13 8.8.8.8 53825 53 242.76560997962952 udp
192.168.56.13 8.8.8.8 53985 53 190.9076578617096 udp
192.168.56.13 8.8.8.8 54879 53 8.994098901748657 udp
192.168.56.13 8.8.8.8 54881 53 8.196769952774048 udp
192.168.56.13 8.8.8.8 55460 53 329.8128139972687 udp
192.168.56.13 8.8.8.8 55551 53 87.19711589813232 udp
192.168.56.13 8.8.8.8 55743 53 174.3170828819275 udp
192.168.56.13 8.8.8.8 56086 53 159.72311305999756 udp
192.168.56.13 8.8.8.8 56197 53 79.90013384819031 udp
192.168.56.13 8.8.8.8 56202 53 225.48099398612976 udp
192.168.56.13 8.8.8.8 56770 53 268.44924092292786 udp
192.168.56.13 8.8.8.8 56908 53 192.60033988952637 udp
192.168.56.13 8.8.8.8 57065 53 127.0586929321289 udp
192.168.56.13 8.8.8.8 57310 53 35.169111013412476 udp
192.168.56.13 8.8.8.8 57415 53 36.10378384590149 udp
192.168.56.13 8.8.8.8 57885 53 329.1409330368042 udp
192.168.56.13 8.8.8.8 58070 53 206.9763388633728 udp
192.168.56.13 8.8.8.8 58554 53 311.89040303230286 udp
192.168.56.13 8.8.8.8 58920 53 50.90778589248657 udp
192.168.56.13 8.8.8.8 59610 53 145.3393590450287 udp
192.168.56.13 8.8.8.8 60389 53 260.0568690299988 udp
192.168.56.13 8.8.8.8 60543 53 112.64408898353577 udp
192.168.56.13 8.8.8.8 60780 53 156.36545395851135 udp
192.168.56.13 8.8.8.8 60910 53 52.557018995285034 udp
192.168.56.13 8.8.8.8 61004 53 98.25972104072571 udp
192.168.56.13 8.8.8.8 61279 53 358.60385298728943 udp
192.168.56.13 8.8.8.8 61800 53 173.65677189826965 udp
192.168.56.13 8.8.8.8 61897 53 221.36074900627136 udp
192.168.56.13 8.8.8.8 62422 53 208.18427395820618 udp
192.168.56.13 8.8.8.8 62491 53 277.3072669506073 udp
192.168.56.13 8.8.8.8 62493 53 21.65089201927185 udp
192.168.56.13 8.8.8.8 62729 53 344.25152802467346 udp
192.168.56.13 8.8.8.8 62849 53 18.806320905685425 udp
192.168.56.13 8.8.8.8 62980 53 239.6432249546051 udp
192.168.56.13 8.8.8.8 63240 53 346.41752195358276 udp
192.168.56.13 8.8.8.8 63617 53 363.6927070617676 udp
192.168.56.13 8.8.8.8 64533 53 104.5568790435791 udp
192.168.56.13 8.8.8.8 64642 53 294.57573890686035 udp
192.168.56.13 8.8.8.8 64700 53 254.03166890144348 udp
192.168.56.13 8.8.8.8 64801 53 65.32386302947998 udp
192.168.56.13 8.8.8.8 64886 53 139.07326006889343 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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