Hackers Exploit PDFs to Impersonate Microsoft, DocuSign, and Others in Callback Phishing Schemes
Cybersecurity experts have raised alarms about phishing campaigns that mimic well-known brands, deceiving victims into calling phone numbers managed by cybercriminals. According to Cisco Talos researcher Omid Mirzaei, “A notable percentage of email threats featuring PDF payloads persuade victims to dial adversary-controlled numbers, showcasing a prevalent social engineering tactic referred to as Telephone-Oriented Attack Delivery (TOAD) or callback phishing.” An analysis of phishing emails with PDF attachments from May 5 to June 5, 2025, found that Microsoft and DocuSign were the most frequently impersonated brands. Other notable targets in TOAD emails included NortonLifeLock, PayPal, and Geek Squad. This surge in activity forms part of broader phishing efforts that leverage the trust associated with popular brands to provoke harmful actions. Typically, these messages include PDF attachments…
Hackers Target Users with PDF-Based Callback Phishing Impersonating Microsoft and DocuSign July 2, 2025 Recent findings from cybersecurity experts highlight an alarming trend in phishing attacks that exploit the trust associated with reputable brands such as Microsoft and DocuSign. These campaigns leverage PDF attachments to manipulate unsuspecting victims into calling…
Hackers Exploit PDFs to Impersonate Microsoft, DocuSign, and Others in Callback Phishing Schemes
Cybersecurity experts have raised alarms about phishing campaigns that mimic well-known brands, deceiving victims into calling phone numbers managed by cybercriminals. According to Cisco Talos researcher Omid Mirzaei, “A notable percentage of email threats featuring PDF payloads persuade victims to dial adversary-controlled numbers, showcasing a prevalent social engineering tactic referred to as Telephone-Oriented Attack Delivery (TOAD) or callback phishing.” An analysis of phishing emails with PDF attachments from May 5 to June 5, 2025, found that Microsoft and DocuSign were the most frequently impersonated brands. Other notable targets in TOAD emails included NortonLifeLock, PayPal, and Geek Squad. This surge in activity forms part of broader phishing efforts that leverage the trust associated with popular brands to provoke harmful actions. Typically, these messages include PDF attachments…