A recent security report has revealed that at the end of December, some* visitors to Yahoo.com were infected by malware by simply visiting the site.
This is another glaring example of the security headache Java has become and how malicious code can slip past players like Yahoo. It is assumed that the malicious code got through by being delivered inside an advertisement displayed on the Yahoo pages. Since then, Yahoo has tightened security on advertisements as well as reviewed security practices.
At its peak, it was estimated that around 27,000 infections per hour were being driven by the malware insertion on Yahoo. Most users seemed to be in Romania, Great Britan and France.
If you are a Yahoo user and visited the site after December 30, 2013 then you are advised to make sure you antivirus software is up to date and recently scanned. If in doubt, you are encouraged to contact an IT professional to ensure you are not at risk.
The malware seems to be financially motivated according to security firm Fox-IT.
*Those visitors had to have Java Web Browser extentions enabled – not everyone was compromised.
Anyone using Java is encouraged to ensure that web extensions are disabled and that you are using the latest version of Java if it is absolutely necessary.