Trustwave has acquired Breach Security for an undisclosed sum, an acquisition that the company said would bring Breach Security's Web application firewall together with Trustwave's own enterprise security tools.

Trustwave will continue to sell and support Breach Security's Web application firewall, which is designed to filter out attacks that could give hackers access to personal customer data and to an enterprise's internal systems, the company said in a press release. Trustwave will also add that firewall technology to the suite of programs offered through its SpiderLabs unit. The suite includes penetration testing, secure code review, incident response and software development training.

A Web application firewall combined with application penetration testing can offer greater protection from Web-based attacks such as SQL injection, which is used to exploit vulnerabilities in the database layer of an application, Trustwave said.

The acquisition continues a buying spree by Trustwave, based in Chicago, which sells products and services for compliance as well as security. Last September it bought Vericept, a vendor of data-loss prevention (DLP) technology, with an eye to better serving companies that need to comply with the payment card industry's Data Security Standard. Trustwave said it would continue to market Vericept's standalone DLP products. In January, Trustwave acquired encryption vendor BitArmor. Terms were not disclosed for either of those deals.

Technology mergers and acquisitions declined during the recession but are now on the upswing. Security companies are involved in the trend, with McAfee announcing last month that it is acquiring Trust Digital.