pbupdate.exe is a legitimate file that was published by iPass. This file is related to iPassConnect Phonebook and used to maintain this app always up-to-date.
However, not long ago iPass detected a problem in using the pbupdate.exe in iPassConnect variations 3.2. This problem results in misleading Pbupdate.exe update error that many users have been receiving on their desktops. If you have also been tricked by such alert, there is a huge possibility that you have downloaded malware on your computer.
Because of its ability to connect itself to the Internet, pbupdate.exe has also been used by scammers to download malicious files on the system and then hide their activity there. If you see several pbupdate.exe file copies running in the backdoor of your operating system, you must check them if they are not infected. We recommend running a full system scan with reputable anti-malware tools, such as Reimage or other listed below.