Microsoft: Hackers abuse OAuth error flows to spread malware
Summary
Attackers are exploiting a vulnerability in OAuth's error redirection process to trick users into visiting malicious websites. This technique bypasses common email and browser phishing defenses, allowing for the distribution of malware. Microsoft has identified and is addressing this threat.
IFF Assessment
FOE
The abuse of a legitimate authentication mechanism to distribute malware represents a new and effective attack vector that defenders must now contend with.
Defender Context
Defenders should be aware of this evolving attack vector that leverages OAuth to circumvent existing security controls. Monitoring for unusual redirection patterns and educating users about potential phishing attempts, even those that appear to originate from legitimate services, will be crucial.