It's Trusteer/Rapport that says you can use it on an infected system and it will protect your data:
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www.trusteer.com/solutionquote:
Rapport assumes the desktop is infected. And, rather than try to clean malware from the desktop, Rapport builds a "secure pipe" inside the desktop which hides credentials and communication with the Website from malware and fraudulent Websites. Malware, or any other form of attack, cannot penetrate the secure pipe and cannot interfere with online banking activities.
In my opinion, if a security product is saying that their software will protect your data even if your system is infected, you should run, not walk, to a serious security product. I would have nothing to do with it, or with any company relying on that product to protect you.