European aeronautical supplier's website infected with state-sponsored zero-day exploit, Sophos reports

IT security and data protection firm Sophos is advising computer users and administrators to exercise caution following the discovery of an as-yet unpatched security vulnerability in Microsoft software.

Sophos Labs today determined that the website of a European aeronautical parts supplier - which is currently not being named due to the sensitivity of the situation - had been hacked, and a malicious attack planted on the website which exploits a zero-day Microsoft security vulnerability.

Sophos was alerted to the security problem when a Sophos customer attempted to visit the affected website, and received a warning message that a file on the site was infected by code which attempts to exploit a vulnerability in Microsoft XML Core Services which could allow Remote Code Execution - a vulnerability known as CVE-2012-1889 - which has been linked to recent warnings from Google about 'state-sponsored attacks'.

"One way that hackers break into large companies and organisations is to target their supply chain.  It's reasonable to speculate that whoever was behind this attack actually had bigger fish to fry - the type of businesses that regularly visit the websites of aeronautical suppliers, such as defence companies," said Graham Cluley, senior technology consultant at Sophos.  "The theory goes that rather than try to hack a company which may have robust security practices and security teams, the bad actor can instead attack a smaller supplier who are less well placed to notice the security breach."

Users running any flavour of currently-supported Windows are vulnerable, from XP, up to and including Windows 7.  All supported editions of Microsoft Office 2003 and Microsoft Office 2007 are also vulnerable.  There is not yet an official patch from Microsoft - but the company recommends that Internet Explorer and Microsoft Office users immediately install a Fix it solution, downloadable with instructions from Microsoft Knowledge Base Article 2719615, until the company issues an official fix.

"Don't underestimate the seriousness of this vulnerability," continued Cluley.  "It's being actively exploited in the wild, and there is currently no patch available for it.  As a result, Sophos has raised its threat level rating to its highest level - 'Critical'.  Sophos does provide protection against the exploit - but the best solution of all would be to have a proper fix from Microsoft.  And for now, at least, we're waiting to see when that's going to appear."