The German and French governments have advised against using Microsoft’s Internet Explorer browser in the wake of a major cyberattack on Google and other organisations last month.

Microsoft admitted last week that the December attack exploited a security issue in older versions of the software, but insisted that there was no risk from using the latest releases, Internet Explorer 8 and 9.

Despite this, Germany’s Federal Office for Information Security wrote on its official website that even running the most up to date version of the browser in ‘Safety Mode’ cannot guarantee security, instead suggesting that users download an alternative. France’s CERTA agency, which monitors foreign cyber threats, issued a similar statement, urging users to switch to a different browser until the issue is resolved.

Microsoft has defended its browser, suggesting that similar flaws could exist in rival software, such as Mozilla Firefox and Google’s Chrome. “It is important to note that all software has vulnerabilities and switching browsers in an attempt to protect against these highly publicised, but currently limited attacks, can inadvertently create some false sense of security,” the company responded in a statement.

Internet Explorer is currently the world’s most popular browser, with a 62.7% market share, followed by Mozilla Firefox at 24.6%, and Google’s Chrome with 4.6% of users.