Eight times more malicious email attachments spammed out in Q3 2008, Sophos reports

October 27, 2008 Sophos Press Release

IT security and control firm Sophos has released the results of its investigation into the latest spam trends and revealed the top twelve spam-relaying countries for the third quarter of 2008.

The figures show an alarming rise in the proportion of spam emails sent with malicious attachments between July - September 2008, as well as an increase in spam attacks using social engineering techniques to snare unsuspecting computer users.

Sophos's latest report reveals that one in every 416 email messages between July and September contained a dangerous attachment, designed to infect the recipient's computer - a staggering eight-fold rise compared to the previous quarter where the figure stood at only one in every 3,333 emails.

Sophos has identified that much of this increase can be attributed to several large-scale malware attacks made by spammers during the period. The worst single attack was the Agent-HNY Trojan horse which was spammed out disguised as the Penguin Panic Apple iPhone arcade game.

Malicious email posing as a Penguin Panic arcade game.
Malicious emails were spammed out posing as a Penguin Panic arcade game.

Other major incidents included the EncPk-CZ Trojan which pretended to be a Microsoft security patch, and the Invo-Zip malware, which masqueraded as a notice of a failed parcel delivery from firms such as Fedex and UPS.

Windows users opening any of these attachments exposed their PCs to the risk of infection and potentially put their identity and finances at risk. The most widespread attacks seen by Sophos are not designed to run on Unix and Mac OS X.

"For Apple Mac and Unix lovers, these major spam attacks just mean a clogged-up inbox, not an infected operating system. But organized criminals are causing havoc for Windows users in the hunt for cold hard cash," said Graham Cluley, senior technology consultant at Sophos. "Too many people are clicking without thinking - exposing themselves to hackers who are hell-bent on gaining access to confidential information and raiding bank accounts. The advice is simple: you should never open unsolicited attachments, however tempting they may appear."

Creative social engineering continues to out-fox users

As well as using malicious email attachments, cybercriminals have continued to embed malicious links and spam out creative and timely attacks designed to prey on users' curiosity.

For example, in August, Sophos warned of a widespread wave of spam messages claiming to be breaking news alerts from MSNBC and CNN. Each email encouraged users to click on a link to read the news story, but instead, took unsuspecting users to a malicious webpage which infected Windows PCs with the Mal/EncPk-DA Trojan horse.


A Sophos video shows how the CNN malware campaign, spammed out in July, worked.

"When a spam email appears to come from a trusted source, too many users are fooled and end up clicking through to a malicious webpage," remarked Cluley. "The naivety shown by many internet users is downright dangerous. In the past hackers were more like teenage mischief-makers breaking into sheds to see what they could find. Today they're hardened criminals wearing hobnail boots with no qualms about breaking into your home and stealing everything they can get their hands on."

New frontiers

Spammers have proven themselves to be unafraid of trying new methods of distributing their marketing messages and spreading their malware to an undefended public during the last three months. Sophos has seen an escalation in the amount of spam being sent via social networking websites such as Facebook and Twitter, and expects to see this continue to rise.

Malicious Facebook message.
Malicious messages are being spammed out via Facebook from compromised accounts.

Emerging countries surface as spam-relaying offenders in dirty dozen chart

This quarter's report has seen three new entries to the spam hall of shame - Colombia and Thailand, have assumed eleventh and twelfth place respectively, while India has shot straight into the chart at number seven.

"Insecure computers, wherever they are in the world, are a spammer's dream - they can be easily hijacked remotely and joined to sprawling networks of botnets designed to create chaos by sending floods of spam and carrying out denial-of-service attacks," explained Cluley. "The message needs to be heard loud and clear: if you don't properly defend your PC you are not only putting your data, finances, and identity at risk, you are also endangering other members of the internet."

Sophos identified the top twelve countries responsible for relaying spam across the globe between July-September 2008:

Whilst the United States retains its position as the top relayer of spam, Russia has increased its contribution to the world spam problem, soaring from 4.4 percent last year, to 8.3 percent during this time period.


A video showing how Sophos tracks spam-relaying compromised PCs around the world using Google Earth.

Spam relayed by continent, July-September 2008

Sophos determined the top continents responsible for relaying spam around the world between July-September 2008:

According to Sophos researchers there is no sign that recent legal action by the authorities against major spam gangs have had any perceptible impact on the amount of spam in circulation.

Sophos recommends companies automatically update their corporate virus protection, and run a consolidated solution at their email and web gateways to defend against viruses and spam.