The term "upd" often refers to an update process on these sites. They may ask you to "verify" your device by downloading other apps or completing surveys. This is a common tactic to generate ad revenue or distribute malware.
Due to the nature of system tweaking, many legitimate optimization tools are flagged by antivirus software (false positives). However, this also makes them a target for malicious cloning. Follow this step-by-step guide for a safe update: mytweaksvip mytweaksvip upd