If you are installing ESET on a computer that has no internet access at all, you need the "Offline Installer." This comes pre-packaged with the latest virus definitions at the time of download.
Updates from unofficial Facebook links carry significant security risks. They may contain malware disguised as update files or be outdated, leaving the system vulnerable to newer threats. Official ESET Stance on Offline Updates eset nod32 offline update facebook
For Facebook users specifically, the benefits are tangible. Many social media threats, such as keyloggers that steal passwords or infostealers that hijack accounts, rely on exploiting outdated antivirus defenses. A fully updated ESET NOD32 offline installation can detect and block known Facebook scam links, fake friend requests, or rogue applications seeking permissions. Furthermore, because offline updates do not require continuous background downloading, they conserve bandwidth for the one online activity that matters most: accessing Facebook itself. If you are installing ESET on a computer