PUB file deliver a backdoor which is capable of setting sensitive informations from corporate information. When the victim opens the file PUB. file it triggers a VBscript and downloads CAB file. Backdoor Trojan can act as a keystroke recorder and record passwords typed into GET forms. It can also gather system information and more from browsers and email clients. The Trojan is also capable of running an AutoIt script and another file encrypted with. AES-256 algorithm. Bitdefender spotted by security experts at BitDefender.”]
Source: https://gbhackers.com/malcrafted-microsoft-publisher-filespub-delivering-backdoor-torjan/