Threat Database Trojans Trojan.Agent.TMS

Trojan.Agent.TMS

By CagedTech in Trojans
Published:

Threat Scorecard

Threat Level: 80 % (High)
First Seen: February 23, 2026
Last Seen: October 23, 2026
OS(es) Affected: Windows

Trojan.Agent.TMS is a Windows-based Trojan horse classified as a high-risk threat, carrying a danger rating of 8 out of 10. Like other members of the Agent Trojan family, it is designed to infiltrate a computer quietly, avoid detection, and then carry out a range of malicious activities in the background without the user's knowledge or consent. Its presence on a system should be treated as a serious security incident.

What Trojan.Agent.TMS Does

Once installed, Trojan.Agent.TMS runs silently in the background, often disguising itself to blend in with legitimate system processes. Notably, samples of this threat have been observed carrying file version information that mimics a "Windows Update Service Host" component, complete with fake company and product details designed to make the file appear to be a trusted Microsoft process. This is a common trick used by Trojans to avoid raising suspicion among users and to slip past casual inspection.

Behind this disguise, Agent.TMS performs harmful functions that can give attackers significant control over an infected machine. This can include covertly deleting files, installing additional malware onto the system, and potentially allowing remote attackers to take control of the compromised computer. Because the Trojan operates without a visible interface and does not announce its presence, victims often have no indication that these actions are taking place until damage has already been done.

How It Usually Gets onto Computers

Trojan.Agent.TMS typically spreads through methods common to this category of malware. It often exploits unpatched system vulnerabilities and security flaws to install itself without permission. It can also arrive bundled with software downloaded from malicious or compromised websites, or hidden inside email attachments sent from untrusted or unknown sources. These attachments may be disguised using file extensions such as .exe, .pif, .avi, or even .jpg in an attempt to trick recipients into opening them.

Risks for the User

The risks associated with Trojan.Agent.TMS are severe. Because it may allow attackers to gain extensive control over an infected system, victims risk having personal files deleted, additional malicious programs silently installed, and their system resources hijacked for further malicious activity. An infected machine can also serve as a launching point for further attacks, data theft, or participation in larger malicious networks without the owner's knowledge.

Signs of Infection

Because this Trojan is built to run stealthily, it may not produce obvious symptoms. However, users of infected systems may typically notice unusual system slowdowns, unexpected background processes consuming resources, new or unfamiliar files appearing, programs crashing unexpectedly, or security tools being disabled. Unexplained changes to files or the sudden appearance of unknown software can also be warning signs typical of this type of infection.

How to Stay Protected

To reduce the risk of infection, users should keep their Windows operating system and all installed software fully updated with the latest security patches, since Trojans like Agent.TMS often rely on known vulnerabilities. Avoid downloading software from untrusted or unofficial websites, and never open email attachments from unknown or unverified senders, especially executable files or files with unusual extensions. Maintaining regular backups of important data, using a reputable security solution, and practicing cautious browsing habits are essential steps in defending against this type of serious Trojan threat.

Analysis Report

General information

Family Name: Trojan.Agent.TMS
Signature status: No Signature

Known Samples

MD5: 036f3dcafeea183cfc146df398efd7cf
SHA1: b56c06442cd3e020150b85f0bab005767ffcd65a
SHA256: 0F4B3440DFBA4F51DADED8FEC1ED0A10B26ADBC617850EDA85ECD247B816D11D
File Size: 86.02 KB, 86016 bytes

Windows Portable Executable Attributes

  • File doesn't have "Rich" header
  • File doesn't have debug information
  • File doesn't have exports table
  • File doesn't have security information
  • File is 64-bit executable
  • File is either console or GUI application
  • File is GUI application (IMAGE_SUBSYSTEM_WINDOWS_GUI)
  • File is Native application (NOT .NET application)
  • File is not packed
  • IMAGE_FILE_DLL is not set inside PE header (Executable)
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  • IMAGE_FILE_EXECUTABLE_IMAGE is set inside PE header (Executable Image)

Windows PE Version Information

Name Value
Company Name Microsoft Corporation
File Description Windows Update Service Host
File Version 21.1.15071.393
Internal Name wuauserv
Legal Copyright (c) Microsoft Corporation. All rights reserved.
Original Filename wuauclt.exe
Product Name Windows Update Agent
Product Version 21.1.15071.393

File Traits

  • x64

Block Information

Total Blocks: 681
Potentially Malicious Blocks: 186
Whitelisted Blocks: 456
Unknown Blocks: 39

Visual Map

0 - Probable Safe Block
? - Unknown Block
x - Potentially Malicious Block

Windows API Usage

Category API
Syscall Use
  • ntdll.dll!NtFreeVirtualMemory
  • ntdll.dll!NtSetEvent
  • ntdll.dll!NtSetInformationWorkerFactory
  • ntdll.dll!NtTestAlert
  • ntdll.dll!NtWaitLowEventPair
  • ntdll.dll!NtWriteFile
  • UNKNOWN