Our partner SonicWall has revealed that the use of malware-laden PDF email attachments has spiked in recent months. Over the course of 2018, SonicWall detected 47,000 new attack variants using PDFs, while they observed more than 73,000 of these variants in March 2019 alone. 67,000 of these PDFs linked to scammers, while 5,500 contained links to malware downloads.
Most of the attacks observed by SonicWall simply used PDFs to smuggle malicious links through email security filters. Many security filters struggle to analyse content inside PDFs, so an attacker stands a better chance of getting through to their victim if they place the link in one of these files. SonicWall CEO Bill Conner said that PDFs are increasingly becoming a “vehicle of choice for malware and fraud in the cyber landscape,” alongside emails and Office documents.
SonicWall notes that PDFs are generally thought of as a safe file type, so users often don’t hesitate to open them. Given the pervasiveness of PDFs within corporate and government environments, employees need to know how to avoid these attacks.