The increase of these bogus ActiveX templates is due to the fact that despite they are currently available for sale, buyers appear to be leaking them for everyone to use so that they can continue maintaining their current business models, namely, the services they offer with the ActiveX templates. Unethical competitive practices among cybercriminals and scammers are only to starting to take place with one another trying to ruin or extend the lifecycle of their services.
Talking about prevalence, the TonsOfPorn ActiveX remains the most widely used rogue ActiveX in the majority of fake codec campaigns for the last couple of months. The ActiveX is largely abused by using another fake porn site template for PornTube, which in combination result in nothing more than huge domain portfolios with no content at all if we exclude the Zlob variants.
And while template-tization means more efficient malware campaigns, it also results in a common pattern for generic detection of such sites. For instance, the folks at Finjan did an experiment by verifying the signature based detection of the common javascript file that was used in the ongoing waves of SQL injection attacks. Their conclusion :
"Can it be that Anti-virus products are now holding more signatures for domains and URLs rather than trying to identify a malicious code they never inspected before? As my research found, just by changing the domain names, some AVs did not find this code as malicious...... surprisingly enough."
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Getting back to the TonsOfPorn ActiveX, it's structure is more static than a Red Army statue in Estonia, making it easy to proactively protect against, no matter the domain, no matter the exploits served. It's detection rate is close to the javascript from the SQL injection attacks - Scanners Result: 9/33 (27.28%) and is detected as Trojan.HTML.Zlob.L.
From my personal experience, blocking an IP address where a couple of hundred malicious domains remain parked, is just as useful as blocking a single domain acting as the main redirector behind a huge domains portfolio of malicious domains. However, the most beneficial approach on a large scale remains the practice of taking care of the most obvious patterns that still remain faily easy to detect, at least for the time being, due to the efficiency the people behind them aim to achieve, making them easily susceptible to generic detection approaches.