Metropolitan Police officers swooped in a morning raid on a man and woman, both aged 20, arresting them on suspicion of distributing the Trojan horse, which attempted to acquire a computer users login details for e-mail, social media and online banking software.

Both were reportedly arrested on November 3 but were later released on bail pending further enquiries.

Zeus (also known as Zbot, PRG, Wsnpoem and Gorhax), gained notoriety due to the manner and scale of which it spread via drive-by-download, which typically means that the program was downloaded when the user believed that they were downloading another file, such as an email attachment, which was infected with the Trojan. The program then hid itself on a user’s PC, logging keystrokes whenever a user was promoted to enter login credentials, such as for online banking, social media or email.

The Trojan, first discovered in July 2007, went on to claim a number of high-profile victims in the space of just two years, including NASA, ABC, Bank of America, Oracle, Amazon.com, Cisco and the US Department of Transportation.

Charlie McMurdie, Detective Superintendent with the Metropolitan Polices’ e-crime unit, noted that the suspects were the first in Europe to be detained over the widespread scam.

Speaking about the gravity of the Zbot Trojan program, she said: “This is known internationally as being a very significant malicious computer programme or malware. It is used for infecting or accessing personal information and in this instance we have 10,000 computers worldwide that have been infected”.

In the seventh biannual Microsoft Security Intelligence Report, the software giant claims that infections from worms have more than doubled between January and June 2009, although Trojans were still the biggest cause for concern. The company also highlighted a notable increase in scareware related infections, where customers are typically persuaded into purchasing bogus antivirus software.

The report claims to have taken extensive coverage of the market, as making use of Microsoft’s comprehensive footprint on consumer as well as corporate computers and the web. Data has also been taken from the company’s Bing search engine as well as various applications, including Live OneCare, Forefront Protection for Exchange cloud service, Malicious Software Removal Tool, and Windows Defender.

The report attributes much of the increase to the ‘Conficker‘ worm, also known as Downadup or Kido and less known ‘Taterf’.

The advice from Microsoft for users was to ensure that they kept an up-to-date antivirus software programme and to exercise caution whilst online.

“We’d recommend, in addition to automatic updates, firewalls and up-to-date anti-virus, that users never log into an account unless they’re on a machine they trust, and don’t download cracks or tips unless from a trusted server,” Cliff Evans, head of Microsoft UK told V3.co.uk.

The X-Force report, compiled by IBM, warned that inserting malicious code in business websites and exploiting flaws in even the most popular browsers are the new methods being increasingly adopted by hackers to distribute spam and malicious software.

During 2008, 55% the 7,406 vulnerabilities tracked by ISS involved web applications and for three in four of these flaws, no security patch existed, giving a strong explanation as to why attacks that result in the planting on malicious code on legitimate websites are such a problem. Such attacks were 30 times more common in the final six months of 2008, according to the report.

Trojan horse programs targeting users of online gaming and banking services made up 46% of all malware tracked by IBM.

Link spamming – the posting of messages promoting malicious websites in the comment section of blogs and news-related websites – more than doubled during the second half of 2008 whilst China overtook the US as the ‘malware hosting capital of the world’ for the first time in 2008.

The increase highlights the need to ensure that your PC is kept up-to-date with the latest software and security patches, including antivirus software, browsers and operating system. For more information on K7 Total Security and Anti Virus, click here.