I have infected computer

Last modified by Denisa Wernerová on 03.08.2023 12:55

Risk of attack the computer can be reduced by following the basic points of prevention. (Prevention - how to secure the computer).

But if your computer will start to behave suspiciously (spontaneously popping browser windows, increased network activity, slowed system etc.), in case that you have been warned of detected suspicious network working from your computer or detected attact on other computers in the University network you have to do the cleaning of your computer or contact your faculty/unit manager.

According to the owner of the computer:

Private computer at home/dormitory:

Update operating system and all installed aplications (mainly Adobe Flash player, Java, browser), antivirus and cleaning/virus removing. If you have troubles with cleaning, please, contact professional service.

To regain your access to the University network tell us via HelpDesk workstation that you did cleaning, updating and securiting your computer. Unfortunately if your security will be low your access to the network will be prohibited again!

Computer owned by University:

If your access to the University network is denied (blocked) due to infection, contact your  faculty/unit manager or your authorized manager.

Procedure for computer virus removing:

  1. You surely do backups of your data. Before cleaning/virus removing backup your data once again.
    • It can happen that system can't be fixed or system may be damaged during repairing so it will be necessary to reinstall the operating system.
    • Your data can be encoded by malware and cannot be fixed. Antimalware tools (antiviruses) mostly solve the file repair by deleting it.
  2. Update your operating system.
    • Clean computer without updates can be attacked from network during a pretty short time (even to 20 minutes). Install operating system and the latest Service Pack without connection to network.
    • Download the latest Service Pack in advance from Microsoft web.
  3. Update !!!all installed software!!!
    • Unpatched installed applications (like Adobe Flash Player, Adobe Reader, Java, Firefox, Chrome, etc.) make attacks from distance much easier.
    • We recommend regular using of programs for detection of unpatched/uncorrected applications - FileHippo Updater, PSI from Secunia, Ninite, etc.
  4. Update antimalware tools (antivirus) and do the thorough check of the computer and portable media (USB keychains, external drivers, etc.).
  5. Study the article Malicious software, SPYWARE, ADWARE etc. including links posted there.
    • Uninstall unnecessary and illegal software many (illegal) programs brings viruses, spyware etc.
    • Try to install some of these programs (e.g. Spybot S&D) according to guide e.g. on spyware.cz - Detection and disposal of vermin and clean your computer.
  6. If malware is irremovable try this:
    • Turn the computer off and take out hard drive with operation system.
    • Plug it into a clean computer with all updates and updated antivirus and even with some program for spyware adware see Malicious software, SPYWARE, ADWARE etc.
    • Do the thorough check of the computer. If system was damaged during cleaning of tested disk it will may be necessary to reinstall it and use the regular backup.
  7. After cleaning your computer it is advised to change all your passwords (mail, ICQ, facebook, internet banking, etc.). It often happens during the attack on the system that your passwords gets stolen and subsequently abused.
  8. Clean temporary files - Temporary Internet Files. Use e.g. program CCleaner which can clean even temporary files of common applications.
  9. Check the installed plugins in web browser (Microsoft IE - Tools → Internet Options → Programs → Manage add-ons)
  10. Follow the security points according to Prevention - how to secure the computer.