Zero-day exploit targets European aeronautical supplier's Web site

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

SophosLabs determined that the Web site 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 Web site that exploits a zero-day Microsoft security vulnerability.

Sophos was alerted to the security problem when a Sophos customer attempted to visit the affected Web site, 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. Rather than try to hack a company which may have robust security practices and security teams, they can instead attack a smaller supplier who is less likely to notice the security breach," says Brett Myroff, CEO of Sophos distributor, NetXactics.

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. At the time of writing 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.

"Users should not underestimate the seriousness of this vulnerability. It's being actively exploited in the wild, and there is currently no patch available for it.

“Sophos has raised its threat level rating to 'Critical'. Sophos does provide protection against the exploit - but the best solution of all would be to have a proper fix from Microsoft,” Myroff says.