Glenn FreemanViruses and spyware targeting PDAs and smart phones are among emerging security threats for businesses and individuals, according to the Sophos security threat report for July 2007.
Despite being a small problem compared with malware targeting Windows-based PCs, Sophos’ January 2007 web survey found 64 per cent of respondents were not currently protecting their PDAs or smart phones from virus or spam threats.
It found the increased uptake of these devices, particularly by business users, and the lack of appropriate protective measures, places them at risk of data theft and damage to business reputation as a result of phone hijacking for unauthorised revenue-generating SMSs
Despite global efforts to develop relevant legislation covering spam, viruses and malware across all types of PCs and hand-held devices , the report found the threat landscape will remain challenging for the foreseeable future.
The advent of spyware and malware delivering viruses to PCs, instead of relying on user download of infected files, is perhaps the biggest change in web-based threats.
Top of the list for web-based threats between January and June 2007 was Mal/frame, a virus program that works by injecting malicious code into web pages.
Interestingly, the Sophos research found sites vulnerable to this type of threat are not necessarily intentionally created this way, with only about one in five infected such sites “malicious by design”. Around 80 per cent of all web-based malware is hosted on innocent but compromised websites.
It also found non-Windows web servers were particularly vulnerable to web-based threats, with over 50 per cent of such threats for January to June 2007 period impacting Apache servers. Many of these are hosted on Linux or other UNIX-based systems, showing infection is not isolated to Windows.
The Sophos study found email threats for the same period remain relatively unchanged from the corresponding period last year, with one out of 322 emails infected for the first half of 2007 relative to 1 in 337 for 2006.
These numbers are down considerably from 2005, when one out of 44 emails was infected, highlighting the different approaches being adopted by offenders.
In the spam stakes, the top three source countries remain the same for the first half of 2007, with the US, China and South Korea topping the list on 19.7 per cent, 7.7 per cent and 6.7 per cent respectively.
One of the new methods spammers are employing in evading filters is the use of PDF files, which are often unreadable for anti-spam products. The increased functionality of PDF files, such as the ability to add clickable links, makes such file types an increasingly attractive option for offenders.