Pidief EI is a Trojan downloader. It gains access into the system through system vulnerabilities and security holes. Pidief EI was designed to perform various malicious actions, but mainly it just downloads more malware, adware or similar parasites. Removal of PidiefEI is essential. Otherwise, PC might be infected with even more dangerous parasites. Please use manual removal guide shown below and remove Pidief EI immediately from the system.
Pidief EI manual removal: