Unearthing a phishing campaign against Calendly

This article discusses the discovery of numerous phishing domains impersonating Calendly to steal user credentials. The investigation was initiated by a tweet and utilized various tools to uncover additional phishing domains linked to a specific IP address. The findings highlight the methods used to track phishing infrastructure and the importance of frequent data updates. Affected: Calendly, users’ cloud accounts, phishing domain infrastructure

Keypoints :

  • Investigation began with a Twitter post by AlphaSOC about a threat actor impersonating Calendly.
  • Phishing domains were discovered that closely mimic the official Calendly homepage.
  • The main IP implicated in the phishing campaign is 154.82.93[.]96.
  • Using Validin’s data revealed an additional 40 domains associated with the phishing IP.
  • Out of the additional domains, 27 were confirmed as Calendly lookalikes.
  • Further analysis showed 84 hosts using identical page titles to Calendly, with 44 suspected to be phishing domains.
  • Another IP address, 78.24.180[.]93, was identified with 406 potentials for phishing, including other popular brands.
  • Validin’s high-frequency data collection allows for rapid tracking of changes in phishing infrastructures.
  • Example phishing domain airplanereference[.]com was shown to have changed content to mimic Calendly.
  • The article emphasizes the need for proactive threat intelligence using tools like Validin.

MITRE Techniques :

  • Phishing (T1566) – Utilized Calendly lookalike domains to trick users into submitting their credentials.
  • Domain Generation Algorithms (T1568) – Multiple lookalike domains were generated and tracked to facilitate phishing attempts.
  • Credential Dumping (T1003) – Aimed at collecting user credential information through impersonation.

Indicator of Compromise :

  • [IP Address] 154.82.93[.]96
  • [IP Address] 78.24.180[.]93
  • [Domain] airplanereference[.]com
  • [Domain] calandly[.]one
  • [Domain] www.calendsly[.]cc

Full Story: https://www.validin.com/blog/finding-calendly-lookalikes/