Perflib_Perfdata_2d8.dat is dangerous file, which should never be kept on the system. In most of the cases, it is installed and used by AntiToolbar. However, there are lots of other cyber threats that have been using this file for initiating various problems on the system. No matter how experienced PC user you are, you can still be tricked into downloading this file on your computer. For avoiding it, please make sure that you have a reputable anti-spyware installed on your machine.
As soon as Perflib_Perfdata_2d8.dat enters computer, it initiates various changes on the system. In most of the cases, it is used for updating the virus, launching it, hiding its files and similar activities. If you noticed unexpected pop-up ads, redirects and similar inconveniences, it's a sign that your machine was affected.
We must also add that sometimes a presence of Perflib_Perfdata_2d8.dat does not indicate that your computer is infected because it can be an essential system file that belongs to harmless and legitimate software. That's why you should always double check the file before uninstalling it from the system. For that we recommend using RegCure Pro.