Cybercriminals are deploying deceptive ads for Microsoft Teams that lead users to malicious software downloads, including ransomware like Rhysida’s OysterLoader. These ads appear prominently in search results and redirect users to counterfeit websites. The malware, often disguised as the legitimate Teams application and signed with counterfeit certificates, can evade antivirus detection and compromise systems. Microsoft has revoked over 200 compromised certificates to disrupt these campaigns and issued warnings about downloading software from unverified sources. The rise of these attacks targets collaboration tools, particularly amid the remote work trend, with hackers exploiting platforms like Teams for espionage and credential theft. Experts recommend navigating directly to official websites and implementing strong endpoint protection to combat these threats.