Security software maker Finjan Inc. released a free browser plug-in on Tuesday to help users avoid clicking malicious links in Twitter that could lead to spyware and malware. The software is called SecureTwitter and is available as part of the Finjan SecureBrowsing plug-in for Firefox and Internet Explorer.

The timing is good, as just today Panda Security put out a warning about malware links in Twitter’s Trending Topics. Panda said to avoid “Twitterbest” and “Zasaden” in Twitter Search, as those are known to contain links that jump to malware sites.

Finjan CTO Yuval Ben-Itzhak said “Reading the recent reports about the proliferation of tweets containing criminal malware, we have taken immediate action to release the SecureTwitter plug-in which is powered by Finjan’s Secure Browsing as a free download to all users.”

The image below shows how the plug-in works. On Twitter, it provides a green check mark, a yellow question mark, or a red X next to each Twitter link, based on information from Finjan’s database. And when you mouse over the icon it pops up a Finjan dialog box with more information.

In my quick tests the Finjan plug-in didn’t evaluate ever single link. It skipped some, which was odd, and not good if I was an IT manager wanting to deploy this to users. However, I was impressed at how quckly the Finjan plug-in loaded. It did not significantly slow down the loading of Web pages.