Trojan.Exprez.B is a computer threat that infects files with extensions such as .exe, .doc, and .docx. Trojans of this kind are typically using tricks so that user may install them on the computer. This Threat does not only cause damages to affected files, it may also provide some actions that can lead to system malfunction. It is vital to deal with this Trojan at once before it can spread on files inside the computer.
Damage Level: Medium
Systems Affected: Windows 9x, 2000, XP, Windows Vista
If user executes Trojan.Exprez.B, it will create a copy of itself under Users Application folder. Then it will move this file to Windows directory when user restarts Windows. The Trojan will then search for files with extensions like .exe, .doc, and .docx. It will decrypt these files and affix them with harmful code. Affected files will be renamed to Trojans own unique extension. Here are some examples:
Letter.doc turns into Letter.cod.scr
Note.docx turns into Note.xcod.scr
During diagnostic, it was found that removing the Trojan deactivates the encryption for affected .exe files. Thus, there is no need to decrypt infected files in order to run them. However, all MS Word files needs manual reset of extension name.
This kind of Trojan usually spreads through file-sharing networks. In most occasions, Trojan.Exprez.B or other threats of the same kind are embedded into legitimate executable files that users frequently downloads from shared public server. Using an advance technique, it often conceals itself from antivirus software. Spam email message is another channel to distribute the Trojan to unspecified target. It may arrive as an attached file that disguises as item worth opening.
How to Remove Trojan.Exprez.B
1. Temporarily Disable System Restore (Windows Me/XP).
2. To identify even the most recent variant of Trojan.Exprez.B, open your antivirus application and update the virus definitions.
3. Start Windows in Safe Mode with Networking.
- From a power-off state, turn on the computer and press F8 repeatedly.
- Your computer will display Windows Advanced Boot Options menu. Select Safe Mode with Networking.
- System will boot Windows loading only necessary drivers and system files.
4. Open your antivirus program and run a full system scan. After the scan, delete all infected items. If unable to delete, better place them in quarantine. Once the scan is complete please proceed with the next step.
Scan with Norton Power Eraser:
Free tool from Symantec called Norton Power Eraser provides deep scanning technology to detect and remote threats like Trojan.Exprez.B. NPE targets and eliminate threats that regular virus scan fails to identify. Download NPE here.
Important! Because of Norton Power Eraser’s aggressive method, it can select even legitimate files as suspicious. Please use this tool very carefully.
Alternative Removal Method for Trojan.Exprez.B
Option 1 : Use Windows System Restore to return Windows to previous state
If Trojan.Exprez.B enters the computer, there is a big chance that Windows files, registry entries and other essential components are also infected. System Restore can reinstate clean system files by restoring the configuration to an earlier date. The method also replaces compromised files with a clean version. If you have a saved restore point before Trojan.Exprez.B infiltrates the PC, we highly encourage you to execute this procedure if none of the above works. You may proceed with Windows System Restore, click here to see the full procedure.
Option 2 : Trojan.Exprez.B manual uninstall guide
IMPORTANT! Manual removal of Trojan.Exprez.B requires technical skills. Deleting system files and registry entries by mistake may result to total disability of Windows system. We advise you to perform a backup of registry before proceeding with this guide.
1. Kill any running process that belongs to Trojan.Exprez.B.
- Press Ctrl+Alt+Del on your keyboard.
- When Windows Task Manager appears, look for Trojan.Exprez.B files (refer to Technical Reference) and click End Process.
2. Delete all registry entries that belong to this malware.
- Press [Windows Key]+R on your keyboard.
- In the 'Open' dialog box, type regedit and press Enter. This will open registry editor.
- Find and delete registry entries as mentioned in Technical Reference section below.
- Close registry editor. Changes made will be save automatically.
3. Scan the computer with antivirus program.
- Connect to Internet and open your antivirus software. Please update to obtain the latest database and necessary files.
- Restart the computer in Safe Mode.
- Just before Windows logo begins to load press F8 on your keyboard.
- On Windows Advanced Boot Options, select Safe Mode and press Enter.
4. Delete all files dropped by Trojan.Exprez.B.
- While still in Safe Mode, search and delete malicious files. Please refer to 'Technical Reference'. Make sure that you execute 'End Task' first before deleting the file. Otherwise, the system will not let you perform this action.