Kaspersky Lab has released new figures showing software exploit attacks increased by almost a quarter in 2016. In total, more than 702 million attempted software exploit attacks were performed; a rise of 24.54% year on year. Corporate users were the worst affected, registering 690,000 attacks in 2016; a rise of 28.35% year on year.

According to the report, 69.8% of software exploit attacks took advantage of flaws in web browsers, Microsoft Windows, Microsoft Office or the Android platform. Software exploit attacks involve malware leveraging flaws in software to run malicious code or install other malware. Last year, the most common exploit took advantage of the Stuxnet vulnerability on unpatched systems.

Software exploits are difficult to identify because they occur silently without alerting the user. Unlike email-based attacks, software exploits require no user interaction. A user must only be convinced to visit a website hosting an exploit kit. A hyperlink can be sent via email or users can be redirected to malicious sites using malvertising. Attacks can occur through general web browsing. Hackers often take advantage of flaws to hijack websites and install exploit kits.

While attacks on companies have increased, attacks on private users fell by around 20% to 4.3 million attacks. This has been attributed to two major exploit kits – Neutrino and Angler – being shut down. Without those exploit kits, criminal groups have lost the ability to spread malware and have had to resort to different tactic to spread malware, with spam email the delivery mechanism of choice.

Exploit kits are expensive to develop and require considerable work, and since software developers are reacting faster and patching vulnerabilities, exploit kits are no longer as profitable for cybercriminals. However, exploits are still being used by sophisticated criminal gangs in targeted attacks aimed at stealing highly sensitive data.

This year has seen an increase in exploit activity using the Rig exploit kit, while last month Checkpoint noted a major rise in software exploit attacks.

Exploit kits may not pose as big a threat as in late 2015, but they are still a significant threat for businesses. Organizations can improve their defenses against software exploits by installing patches promptly and ensuring anti-virus and anti-malware solutions are kept up to date. A web filtering solution should also form part of organizations’ defenses. Web filters prevent end users from visiting, or being redirected to, websites known to host exploit kits.