Crackers are developing more sophisticated techniques for take over the control of corporate databases using malicious code akin to malware already common on Unix platforms. The threat also applies to repository-based software such as CRM systems and web applications, creating a need for new security tools, according to Alexander Kombrust of Red Database Security.
Kombrust told a session at the Black Hat security conference in Amsterdam on Friday, 1 April that operating Systems and databases are quite similar in their architecture. Each has users, processes, jobs and executables. This similarity means forms of malicious code - like rootkits - that have long being a problem for Unix admins are also an issue for database administrators.
Rootkits refer to a set of tools used by crackers after breaking into a computer system to hide logins and processes under the control of an attacker from detection. Kornbrust said a database rootkit for Oracle systems would hide the Oracle execution path, database users, processes and jobs as well as modifying internal functions.
Database rootkits would be implemented by either modifying a database object or changing the execution path, for example by creating a local object with the identical name, establishing a synonym pointing to a different object or switching to a different schema. Thereafter Kornbrust showed how it would be possible for a hacker to hide database users or processes he controlled. Most internal packages from Oracle are protected from modifications but Kombrust emphasised that the threat - although hard to quantify - was real.
"Knowledge is not widespread about how to hack databases but information is out there," said Kombrust. "This is not for script kiddie but internal attack is possible - a professional attacker is very difficult to detect. There are no figures on incidents," he added.
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Kombrust explained how to rootkits/backdoors in a database could be identified using a special tool called repscan, developed by Red Database Security. The tool finds modifications in execution paths and checks for insecure database settings. Ultimately databases or other application should check the repository for modifications themselves, according to Kombrust, who added that the rootkit threat ought to prompt more secure coding practices among developers. ®