Malicious actors leveraged phishing emails designed to look like they originated from the Supreme Court in order to steal victims’ Office 365 credentials.

Armorblox detected a phishing campaign that attempted to steal victims’ Office 365 credentials by masquerading as a subpoena from the Supreme Court. The attack emails sent via this operation leveraged “Supreme Court” as their sender name along with authoritative language to trick recipients into clicking on a “View subpoena” button. This button redirected recipients to a phishing page hosted on the domain “invoicesendernow[.]com” for the purpose of stealing their Office 365 credentials.

A closer look revealed that this operation employed multiple techniques to bypass email gateways and other security controls. First, it targeted only a few users in each organization to avoid raising red flags. Second, the campaign’s penultimate redirect sent users to a functioning CAPTCHA page. This asset added legitimacy to the operation as well as helped it to evade detection by email security technologies.

Other Recent Attempts to Steal Office 365 Credentials

Back in December 2019, PhishLabs spotted a similar campaign that leveraged a malicious Office 365 app in order to steal access to a victim’s account without lifting their credentials. That was about a month before Avanan revealed that it had discovered malicious actors abusing Microsoft Sway to target users’ Office 365 details. In April 2020, Group-IB detailed the efforts of one “PerSwaysion” campaign to abuse Microsoft Sway as a means of redirecting users to a fake Office 365 login page.

Defend Against a Phishing Attack

Security professionals can help their organizations defend against a phishing attack by conducting ongoing security awareness training with their employees. These exercises can help educate the workforce about some of the most common types of phishing attacks in circulation today. In addition to human controls, infosec personnel should leverage technical measures that help block email messages from blacklisted and/or typosquatting domains.