Global analysis of 10 million web attacks | ICT Security-Sécurité PC et Internet | Scoop.it
Web applications, on average, experience twenty seven attacks per hour, or roughly one attack every two minutes, according to Imperva. They observed and categorized attacks across 30 applications as well as onion router (TOR) traffic, monitoring more than 10 million individual attacks targeted at web applications over a period of six months.

The analysis shows:
When websites came under automated attack they received up to 25,000 attacks in one hour, or 7 attacks every second.

Four dominant attack types comprise the vast majority of attacks targeting web applications: Directory Traversal, Cross-Site Scripting, SQL injection, and Remote File Inclusion.