Malware type: Trojan

Aliases: No Alias Found

In the wild: Yes

Destructive: No

Language: English

Platform: Windows 98, ME, NT, 2000, XP, Server 2003

Encrypted: No

Overall risk rating:

Reported infections:

Damage potential:


Distribution potential:



A Trojan horse program is a malware that is not capable of automatically spreading to other systems. Trojans are usually downloaded from the Internet and installed by unsuspecting users.

Trojans typically carry payloads or other malicious actions that can range from the mildly annoying to the irreparably destructive. They may also modify system settings to automatically start. Restoring affected systems may require procedures other than scanning with an antivirus program.

For additional information about this threat, see:

Description created: Nov. 16, 2009 3:22:04 AM GMT -0800


File type: PE

Size of malware: 18,977 Bytes

Initial samples received on: Oct 27, 2009


This Trojan may be downloaded from remote site(s) by other malware.

It may be dropped by other malware.

It may be downloaded unknowingly by a user when visiting malicious Web site(s).

This Trojan may be used by other malware in performing their malicious routines.

It requires other components in order to run properly.

Analysis By: Marfel Tiamzon

Revision History:

First pattern file version: 6.694.02
First pattern file release date: Dec 15, 2009


Minimum scan engine version needed: 8.900

Pattern file needed: 7.595.00

Pattern release date: Nov 4, 2010

Important note: The "Minimum scan engine" refers to the earliest Trend Micro scan engine version guaranteed to detect this threat. However, Trend Micro strongly recommends that you update to the latest version in order to get comprehensive protection. Download the latest scan engine here.


For Windows ME and XP users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

 Step 1: Identify and terminate files detected as TROJ_AGENT.AYAA  [learn how]


  1. For Windows 98 and ME users, Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

 Step 2: Scan your computer with your Trend Micro product to delete files detected as TROJ_AGENT.AYAA  

*Note: If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.

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