More than 10-million zombie computers were sending spam and e-mails with malware every day during the second quarter of this year.
This is according to the latest report from PandaLabs and Commtouch on the global spam situation.
"Zombie computers are systems infected by 'bots' (short for 'robot') and controlled remotely by cyber criminals. These bots are small programmes dropped on computers that allow attackers to take remote control of the system," says Jeremy Matthews, head of Panda Security's sub-Saharan operations.
"Botnets are groups of computers infected by bots and primed to act in unison. Cyber-crooks send instructions to these computers, including commands to download malware onto the system, display advertising to the user, launch denial of service attacks and – above all – to distribute spam."
In the second quarter of 2008, Turkey became the country with the most zombie computers (11% of the global total), followed by Brazil (8.4%) and Russia (7.4%). The US, which in the first quarter accounted for 5% of all zombies, is now in ninth place with just 4.3% of the total.
This vast number of zombies continues to be largely responsible for the avalanche of spam suffered by users and companies – in the second quarter, an average of 74% of all mail received was spam.
"This is not just annoying for users, who have to delete all of this mail, but in corporate environments it has important repercussions on productivity and resource consumption", says Matthews. Nucleus Research, an independent consultant, has put the cost of receiving and deleting spam at R1 341.00 ($712.00) per employee.
The past few months have revealed no revolutionary new trends in the distribution of spam and malware via e-mail – largely due to the fact that existing methods are still serving cyber-crooks well, says Matthews.
Google Adwords has been at the centre of one of the most notable attacks over the last quarter. Using this Google service to launch phishing attacks continues. This type of attack uses social engineering to trick users into revealing confidential details (bank account numbers, passwords, etc.).
Aimed at the owners of Google Adwords accounts, the messages include subjects such as "your adwords google account is stopped" or "account reactivation" and include seemingly legitimate links. If users click the link, however, they are taken to a page that appears genuine and are prompted to enter their confidential details which will immediately fall into the hands of cyber-crooks
Tax information continues to be another favourite of spammers. In April, coinciding with the period for filing tax returns in the USA and other countries, attackers distributed mail with subjects such as: "Get a fast tax refund free" or "Get fast relief for irs tax debt". In most cases, the aim of these attacks was to obtain confidential details such as bank account numbers or physical addresses.
The Blogspot platform has also been used to host and distribute malicious content. Perhaps as a result of the growing awareness by Blogspot and its attempts to counter this type of content, spammers have begun to use other platforms. Blogdrive fell victim in this second quarter to spammers, who launched a wave of comments at the platform containing links to pornographic websites.