Sophos, a software security company, issued a warning on Friday that a new threat is spreading quickly.

The threat approaches the user as a genuine Microsoft Update, but it is actually a fake anti-virus circulating in the attire of a Microsoft Update, and therefore it has been successful in attracting users into its trap, tech2 reported.

Criminals convince users to believe that the fake anti-virus that they are being asked to download is indeed a genuine Microsoft Update. The virus Microsoft Update pops up only when people are using Mozilla Firefox on Windows. Users familiar with Microsoft Updates would know that they only happen on Internet Explorer. The update shows the exact copy of the Microsoft Update page, and those not well-informed fall prey to such traps.

Sophos, in its warning, also stated that users should not meet the terms of any such security updates unless they have duly checked it with Adobe, Microsoft, or Sophos.