SQL injection (SQLi) attacks rose 69% in the second quarter of 2012 compared with the previous quarter, according to the latest report from secure cloud hosting firm FireHost.
FireHost said that, between April and June, it blocked nearly 500,000 attacks by SQLi, a well-known and popular method used by cyber criminals to steal data and among the most malicious and dangerous web-based attacks.
SQLi involves entering malicious commands into URLs and text fields on vulnerable websites, usually to steal the contents of databases storing valuable data such as credit card details.
Even though websites can be protected easily, the attack method has been associated with many high-profile data breaches, including Sony in 2011.
SQLi is also believed to have played a role in the more recent theft of passwords from LinkedIn, eHarmony and Yahoo.
These attacks are often automated and many website owners may be unaware their data is at risk, said Chris Hinkley, a senior security engineer at FireHost.
"These attacks can be detected and businesses should be taking basic and blanket steps to block attempted SQLi, as well as the other types of attacks we frequently see," Hinkley said.
SQLi attacks, along with cross-site scripting (XSS), directory traversals and cross-site request forgery (CSRF) attacks are the most malicious and dangerous, said FireHost.
Todd Gleason, director of technology at FireHost, said businesses should take readily available and basic steps to block any kind of unwanted traffic from accessing their sites.
"Ensuring web applications are secure can go a long way toward fighting off random automated attacks,” Gleason said.
Earlier this year, a top cyber security risks report by Hewlett Packard revealed that in 2011, SQLi attacks represented the most popular technique used against web applications, with three times as many SQLi attacks than PHP file inclusion and cross-site scripting attacks combined.
"Good software should not introduce security vulnerabilities, yet 86% of web applications analysed had some kind of vulnerability," said Simon Leech, presales director at HP Enterprise Security.
Web application vulnerabilities account for 36% of all vulnerabilities, the report said, exacerbated by customisation and add-ons.