“Harmful software detected” popup is a fake security alert produced by rogue anti-spyware program called System Security. Basically, this fake alert states that your computer is infected with malicious software and that you should use System Security program to remove harmful software form your computer.
“System Security
Harmful software detected
System Security has detected harmful software that can [...]

Grayware: TSPY_SILENTBAN.U

Microsoft Corporation regularly issues updates to fix bugs and security vulnerabilities in its software products. These updates are meant to protect its users from different attacks that depend mainly on exploiting these documented bugs.
Close to the weekend, we identified spam (click Figure 1 thumbnail for larger view) claiming to be a Microsoft Outlook and Outlook [...]

Post from: TrendLabs | Malware Blog - by Trend Micro

“Critical Update” Leads to Critical Info Theft

Contraviro is a fake spyware remover - a clone of Unvirex. This parasite enters the system by using trojans, such as the infamous Zlob, which is the most-used parasite in connection to rogue anti-spyware programs. Contraviro relies on misleading advertising to trick users into purchasing its “licensed version”.
Upon entering the system, Contraviro will flood the user with [...]