Computer security not an exact science
Q: I scanned my computer using Malwarebytes, and it detected something that it identifies as a PUP. I removed it, but when I rebooted and scanned again, the same PUP showed up. What is this, and should I be concerned?
A: In the world of viruses and spyware, a PUP is what’s known as a potentially unwanted program.
A PUP, in and of itself, is not necessarily malicious. It is most often a program that was installed a part of a bundling process when you installed some other program you downloaded from the internet.
The most common PUPs are usually things like toolbar add-ons like Ask or Yahoo. While not dangerous or a sign that your system has been compromised, they can be annoying or create unnecessary clutter to your computer — which is why programs like Malwarebytes detect them and alert you to their presence.
The reason the PUP keeps coming back is likely due to something you have installed on your computer that is replacing it after it is removed using a utility like Malwarebytes.
To be fully rid of it, you will need to determine the underlying program and uninstall it from Add/Remove Programs. You can probably find out what the underlying program is by searching the web, using the name of the PUP that is detected.
To avoid these in the future, it is always a good idea to read each screen presented when installing new software. These screens will usually tell you if something else is being bundled, and you can often opt out of the additional programs.
You should also be aware that many antivirus and anti-spyware programs will often alert on other antivirus and anti-spyware programs indicating you have a problem.
For example, I had a computer with Symantec installed, which was using the Safe Search feature to help protect the web browser, and Malwarebytes kept alerting when it found this during the scan. Since the computer owner wanted to keep the Safe Search feature enabled, he had to learn to ignore this warning in subsequent scans.
Computer security is not an exact science. Antivirus, anti-malware and even anti-spam applications can make mistakes. They often err on the side of caution and can sometimes detect and even prevent things that are not actually a threat.
That is why you should always review what is detected and even go into your spam folder once in a while to make sure you are not blocking something you might actually want.