New favourite for spam and malware attacks: mobile devices

©Michael Heim via 123RF

Among other trends identified in the Kaspersky Lab spam report are the following. Over three quarters (79%) of all emails sent were less than 2kb, which shows a steady decrease in email size for spam campaigns over the past few years. Financial institutions such as banks, payment systems and online shops were attacked most often with phishing emails (34.33%, a rise of 5.59%).

In 2015, cyber criminals continued to send out fake emails from mobile devices and notifications from mobile apps containing malware or advertising messages. New tactics included fraudsters spreading malware in the form of .apk (Android executive files) and .jar (ZIP archives containing a program in Java).

Pay to decrypt files

In addition, cyber criminals masked a mobile encryption Trojan behind a file containing updates for Flash Player. After launching, the malware encrypted images, documents and video files stored on the device with users receiving a message telling them to pay a fee in order to decrypt the files.

“The increased use of mobile devices in our everyday life to exchange messages and data, as well as access and control bank accounts, has also resulted in increased exploitation opportunities for cyber criminals," warns Daria Loseva, spam analysis expert at Kaspersky Lab.

"Mobile malware and fraudulent spam is becoming more popular and efforts to dupe victims are becoming more sophisticated year on year, with the emergence of apps that can be used by cyber criminals both directly (for sending out spam, including malicious spam) and indirectly (via phishing emails). Mobile device users therefore need to be on their guard and remain vigilant, as cyber criminal activities in this area are only likely to increase, along with our reliance on devices.”

The US remained the biggest source of spam (15.2%), with second place taken by Russia (6.15%) and China making way for Vietnam in third spot (6.12%). Germany was the biggest victim with 19.06% of spam attacks - a 9.84% increase on 2014, followed by Brazil at 7.64% which posted a 4.09% increase and moved up from sixth place in 2014. Russia moved up to third place from eighth, an increase of 3.06% to 6.03% of all spam attacks in 2015.

Hot spam topics

'Nigerian' fraud used the Ukrainian political situation, the Syrian civil war, the election in Nigeria and the earthquake in Nepal to exploit the kindness and empathy of recipients with believable email content. These emails contained content calling for material support for a person in need.

Although the Olympic Games in Brazil has yet to take place, fraudsters have already started to exploit the event, sending emails announcing false lottery wins and asking the recipient to fill in a form with their personal details. In these attacks, emails with pdf attachments, pictures and other graphical elements were designed to fool the spam filters.