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🎣 Get in loser, we’re going phishing. This week, we’re going to spotlight how Russian threat actors are phishing targets associated with Ukraine and human rights to abuse Microsoft OAuth.

We’re currently reading Volexity’s recent report: “Phishing for Codes: Russian Threat Actors Target Microsoft 365 OAuth Workflows” www.volexity.com/blog/2025/04...

Russian actors have been spotted conducting highly targeted social engineering operations aimed at gaining access to their target’s Microsoft 365 accounts.

The adversary contacts a victim via Signal or WhatsApp, invites them to a meeting, and sends them an OAuth phishing URL to join. Once the OAuth code is given up, the threat actor can access the victim’s M365 account.

This behavior maps to T1566.003 Phishing: Spearphishing via Service, a technique in which adversaries send messages through various non-enterprise controlled services in large part because they are more likely to have a less-strict security policy than an enterprise. attack.mitre.org/techniques/T...

The world turns, the seasons change, but Russian threat actors targeting Microsoft 365 accounts stays the same. Earlier this year, the same actors were spotted conducting similar attacks also leveraging chat apps like Signal www.volexity.com/blog/2025/02...

Signal is a powerful end-to-end encrypted chat app. At the end of the day, that doesn’t help at all when you’re being spearphished. In fact, the lack of visibility and detection inherent in an encrypted chat app could even potentially hurt. That’s a wrinkle requiring vigilance on all parts.