Cybercrime became suddenly old fashioned in the first three months of 2013, with spam emails and classic malware making huge comebacks.
The amount of spam email messages doubled in the first quarter, with more than 1.9 trillion bogus messages sent in March alone.
That's twice the number recorded in December 2012, which saw the end of a downward spam trend that had lasted for more than a year, said anti-virus software maker McAfee in its newly released Threats Report: First Quarter 2013.
Another oldie but goodie, the venerable but versatile Koobface worm, which attacks social networks on Macs and PCs alike, also experienced healthy growth in the first quarter, much to the dismay of security researchers.
"With Koobface, which plagues Facebook users, we found almost three times as many samples this quarter compared with last quarter. That’s another record high point and double the size of the prior mark, set in the fourth quarter of 2009," the McAfee report said.
Cybercriminals found still another way to go retro from January through March, targeting financial institutions with a new variant of the infamous Citadel banking Trojan, using it to steal data rather than dollars in highly targeted attacks.
"All malware that we track — affecting clients, servers, networks, mobiles — now stands at more than 128 million samples," the McAfee report said, citing rapid growth, particularly in the ransomware and Master Boot Record malware sectors.
"With ransomware, cybercriminals hold a system hostage and insist on payment to unlock a computer. But will they free the machine after the victim pays?" the report asked. "There are no guarantees, and anonymous payment systems make it basically impossible to track their movements."
Master Boot Record malware, which first appeared in the late 1990s, infects the part of a hard disk that tells a computer which operating system to load upon startup.
"MBR threats can remain on a system for a long time without the victim’s knowledge, and download other forms of malware," the McAfee report noted.
Also making a comeback were AutoRun worms, which exploit Windows machines that are set to automatically run software upon the insertion of removable volumes, such as CD-ROMs or USB sticks.
"AutoRun malware, which often hides on USB drives and can allow an attacker to take control of a system, has risen rapidly for two quarters and reached a new high, with almost 1.7 million new threats," the report noted.
In more modern trends, January through March saw continued steady growth in mobile malware, with 30 percent of all active mobile malware appearing for the first time in those 90 days.
That actually represents a slight decrease in the rate of growth from last year, but still puts mobile malware on track to have another record-breaking year.
In 2011, McAfee collected only 792 samples of mobile malware. Since then, the company's library, or "zoo," of mobile malware has grown to hold almost 51,000 samples, almost all of which run on Android.
Despite the popular image of Chinese cyberspies and Russian online criminals, American IP addresses represent both the largest source and the most frequent targets of network attacks, the report found.
The most common attacks are browser based, initiating drive-by downloads using malicious iframe links buried in Web pages, as well as Java code exploits.
The United States also saw a 12 percent uptick in the number of suspicious Web links, which are usually used by phishers to trick victims into giving up personal information or granting access to a secure network.
The report said the sheer number of cybercriminals on the Internet is rising as skilled malware coders make and sell "hack-by-numbers," off-the-shelf malware kits that make the barriers to cybercrime success much easier to overcome.
"Cybercriminals continue to develop and market crimeware tools, which make it easy for inexperienced scammers to join the ranks and exploit victims," the report said.
If the McAfee Threat Report makes one thing clear, it's that those who rely on networked devices need to remain as vigilant as ever against Internet threats.
By regularly updating your computer and smartphone and running a good anti-virus program you can minimize your exposure to most of the malware floating around.
Remain wary when opening emails and clicking on links, and do your best to verify their sources. Criminals are adept at spoofing messages to appear as if they are corporate communications or even personal messages from friends' email addresses.