According to cybersecurity firm Avast , you probably did n't , and that 's the number one cause of cybersecurity incidents . Avast just released a new report , entitled Avast PC Trends Report January 2017 . It is based on insights from the company ’ s AVG TuneUp product , and says that more than half ( 52 per cent ) of the most popular PC applications are outdated . That way , Avast claims , people are exposing Attack.Databreach their data to cybercriminals , as their machines become vulnerable to malware and ransomware . Drawing intel from 116 million Windows machines worldwide , here are the ten most out-of-date programs : “ In the online world , your security habits , such as keeping your software updated , play a big role in your level of your protection on the Internet , ” said Ondrej Vlcek , Chief Technology Officer , GM and EVP Consumer Business at Avast . “ Running outdated programmes leaves PC users susceptible to attacks from savvy hackers exploiting easy-to-find or known vulnerabilities . The cause of people using outdated software may be that updates don ’ t install properly or they postpone or forget to update even when prompted