Link scanners are often wrong but still they are sometimes useful. There are many link scanners on the market, even AVG link scanner has its one, why not Avast? ???
This is the reason why Avast has a web shield
It is able to monitor and filter all HTTP traffic coming from the Web sites on the Internet. Since an increasing number of viruses (and other malware, such as adware, spyware and dialers) are being distributed via the World Wide Web, the need for effective countermeasures has also increased. The Web Shield acts as a transparent HTTP proxy and is compatible with all major web browsers, including Microsoft Internet Explorer, FireFox, Mozilla and Opera.
Unlike most competitive solutions, the Web Shield’s impact on browsing speed is almost negligible. This is because of a unique feature called “Intelligent Stream Scan” that lets the Web Shield module scan objects on-the-fly, without the need of caching them locally. Stream scanning is performed in operating memory only (without the necessity to flush the contents to disk), providing maximum possible throughput rates.
Because we have the web shield and given your choice of browser, Firefox with NoScript your risk is much reduced anyway (RequestPolicy is another you should consider). There are also plenty of link scanners available some as add-ons for firefox.
I really don’t want avast to become bloated and full of all sorts of bells and whistles, especially when the tools (bells and whistles) are available from other areas.
I remember when avg’s link scanner was first introduced, the screams could be heard for miles and they weren’t screams of joy.
In addition to the above posts, you only have to look at the many posts about avast’s Web Shield detecting bad URLs and the OP wanting to know if it is true and, 99.9% of the time, Web Shield is correct.
We only use other URL scanners (unmaskparasites, malwareURL, etc) for a second oppinion to reassure the OP that Web Shield is correct.
With Web Shield active, no other link scanner is needed in the avast arsenal.