The popularity of rogue anti-virus programs, such as Security Tool, or the fake Microsoft Security Essentials clones like Think Point, speaks to the fact that many people are completely oblivious as to how these parasites are to be dealt with. I will therefore try to dispel some misconceptions about these parasites.
First of all, many people believe that it is more than enough to use one security program to get rid of rogue anti-spywares. Basically, they believe that “out of sight” is equal to “out of the system”, which is not true. In many cases a particular anti-spyware may seem to have removed a rogue anti-spyware, but it might leave traces – files, registry entries and so on, but most importantly rootkits and trojans. For those who don’t know what a rootkit is, in layman’s terms, it’s a process that hides from other processes on an system. This process can do a lot of bad things, even allow hacker to have privileged remote access to the system, or download other programs on command. So, basically, if your fail to remove rootkits after an infection, your system might still be part of a botnet, and it might get reinfected.
Multiple security tools generally solve the problem: there are ones that are better against malware, and then there are those, which work better against rootkits – do your research and choose accordingly. The most prevailing rootkit family today is TDSS. These are often the culprit behind browser redirection on systems that have no other infection signs. At the moment good choice of tools would be TDSS Killer together with couple anti-malware tools like Spyware Doctor or Malwarebytes. I have good results with Hitman Pro as well.
This, however, is not the whole story. Another important thing you have to make sure of is that you update your software. Not just windows, but also your other software, especially your browser and browser plug-ins – these may be exploited to infect your system. Keep your system up-to-date and protected, so you will not need to spend long hours repairing it from infections.