According to an analysis conducted by the Kaspersky Lab from Q1 of 2018, Microsoft Office applications are one of the most commonly exploited applications worldwide. A little under half of the complaints Kaspersky received related to Microsoft Office applications. Browser applications came in second with about a quarter of their complaints relating to their vulnerabilities.
Notably, applications interacting with PDFs are prone to cyber-attacks, since PDF files are one of the main file types cybercriminals target for phishing campaigns. Apps working with PDF files made up about 1 percent of the complaints in the report.