Viruses are accidentally infecting worms on victims’ computers, creating super-powered strains of hybrid software nasties.
The monster malware spreads quicker than before, screws up systems worse than ever, and exposes private data in a way not even envisioned by the original virus writers.
A study by antivirus outfit BitDefender found 40,000 such "Frankenmalware samples" in a study of 10 million infected files in early January, or 0.4 per cent of malware strains sampled. These cybercrime chimeras pose a greater risk to infected users than standard malware, the Romanian antivirus firm warns.
“If you get one of these hybrids on your system, you could be facing financial troubles, computer problems, identity theft, and a wave of spam thrown in as a random bonus,” said Loredana Botezatu, the BitDefender analyst who carried out the study. “The advent of malware sandwiches throws a new twist into the world of malware. They spread more efficiently, and will become increasingly difficult to predict.”
BitDefender doesn't have historical data to go on. Even so it posits that frankenmalware is likely to grow at the same rate as regular computer viruses, or about 17 per cent year on year.
All of the malware hybrids analysed by BitDefender so far have been created accidentally. However, the risk posed by these combos could increase dramatically as crooks latch onto the idea of deliberately splicing malware strains together to see what sticks. This is on top of efforts by blackhat coders to add extra features to others' viruses and unleash the updated builds onto the unsuspecting public.
BitDefender carried out its study after finding a sample of the Rimecud worm that was infected by the Virtob file infector. Rimecud is designed to steal online passwords for e-banking or e-mail accounts, among other functions. Virtob creates a hacker-controlled backdoor on infected systems.
"Imagine these two pieces of malware working together - willingly or not - on the same compromised system,” Botezatu explains. “That PC faces a twofold malware with twice as many command and control servers to query for instructions; moreover, there are two backdoors open, two attack techniques active and various spreading methods put in place. Where one fails, the other succeeds."
More details on the threat can be found in a post on BitDefender's Malware city blog here. ®