In April 2025, FortiGuard Labs observed a threat actor using phishing emails with malicious HTML files to spread Horabot, malware that primarily targets Spanish-speaking users. It is known for using crafted emails that impersonate invoices or financial documents to trick victims into opening malicious attachments and can steal email credentials, harvest contact lists, and install banking trojans.
Horabot leverages Outlook COM automation to send phishing messages from the victim’s mailbox, enabl