Step 1: Keep calm, disconnect from the Internet and check your last data back-up
The first thing to do is to disconnect from the Internet (remove your LAN plug or switch the Wi-Fi off). Then you should establish how old your last data back-up is. It is recommended to create an additional, new back-up onto a different storage media from your normal back-up.
Please note: It is possible that you also back up malware when you create such a back-up, but that is irrelevant for the time being.
Step 2: Decide whether you will need a specialist
You should now consider whether you can remove the malware yourself, or whether you want to consult a specialist. There are various anti-virus software manufacturers who offer a special service to remove malware. This often involves a telephone helpline or “remote malware removal”. However, such services are chargeable. As an alternative, there are also various computer specialist stores which offer repair services (especially for malware infections).
Step 3: Identify and remove malware
Certain types of malware can be removed by the anti-virus software installed, but not all of them. If your anti-virus software is unable to remove the malware, it is recommended to use a so-called “second opinion virus scanner”, for instance
If this doesn’t help either, the malware will need to be precisely identified. It is best to use the malware name (as displayed by your anti-virus software) and then research on the Internet (from another non-infected device) for instructions on how to remove this. Most antivirus software manufacturers provide malware data bases including instructions for removal. If your antivirus software manufacturer provides a boot CD, you should try to start your computer from this CD and remove the malware this way.