Antivirus is Dead: Long Live Antivirus!

Krebs on Security by BrianKrebs  /  5/7/14

The Wall Street Journal this week quoted executives from antivirus pioneer Symantec uttering words that would have been industry heresy a few years ago, declaring antivirus software “dead” and stating that the company is focusing on developing technologies that attack online threats from a different angle.
Ads for various crypting services.
This hardly comes as news for anyone in the security industry who’s been paying attention over the past few years, but I’m writing about it because this is a great example of how the cybercrime underground responds to — and in some cases surpasses — innovations put in place by the good guys.
About 15 years ago, when the antivirus industry was quite young, there were far fewer competitors in the anti-malware space. Most antivirus firms at the time had a couple of guys in the lab whose job it was to dissect, poke and prod at the new crimeware specimens. After that, they’d typically write reports about the new threats, and then ship “detection signatures” that would ostensibly protect customers that hadn’t already been compromised by the new nasties.
This seemed to work for while, until the smart guys in the industry started noticing that the volume of malicious software being released on the Internet each year was growing at fairly steady clip. Many of the industry’s leaders decided that if they didn’t invest heavily in technologies and approaches that could help automate the detection and classification of new malware threats, that they were going to lose this digital arms race.
So that’s exactly what these firms did: They went on a buying spree and purchased companies and technologies left and right, all in a bid to build this quasi-artificial intelligence they called “heuristic detection.” And for a while after that, the threat from the daily glut of malware seemed to be coming under control.
But the bad guys didn’t exactly take this innovation laying down; rather, they responded with their own innovations. What they came up with is known as the “crypting” service, a service that has spawned an entire industry that I would argue is one of the most bustling and lucrative in the cybercrime underground today.
Put simply, a crypting service takes a bad guy’s piece of malware and scans it against all of the available antivirus tools on the market today — to see how many of them detect the code as malicious. The service then runs some custom encryption routines to obfuscate the malware so that it hardly resembles the piece of code that was detected as bad by most of the tools out there. And it repeats this scanning and crypting process in an iterative fashion until the malware is found to be completely undetectable by all of the antivirus tools on the market.
Incidentally, the bad guys call this state “fully un-detectable,” or “FUD” for short, an acronym that I’ve always found ironic and amusing given the rampant FUD (more commonly known in the security industry as “fear, uncertainty and doubt”) churned out by so many security firms about the sophistication of the threats today.
In some of the most sophisticated operations, this crypting process happens an entirely automated fashion (the Styx-Crypt exploit kit is a great example of this): The bad guy has a malware distribution server or servers, and he signs up with a crypting service. The crypting service has an automated bot that at some interval determined by the customer grabs the code from the customer’s malware distribution server and then does its thing on it. After the malware is declared FUD by the crypting service, the bot deposits the fully crypted malware back on the bad guy’s distribution server, and then sends an instant message to the customer stating that the malware is ready for prime time.
Crypting services are the primary reason that if you or someone within your organization is unfortunate enough to have opened a malware-laced attachment in an email in the first 12-24 hours after the bad guys blast it out in a spam run, there is an excellent chance that whatever antivirus tool you or your company relies upon will not detect this specimen as malicious.
In short, as I’ve noted time and again, if you are counting on your antivirus to save you or your co-workers from the latest threats, you may be in for a rude awakening down the road.
Does this mean antivirus software is completely useless? Not at all. Very often, your antivirus product will detect a new variant as something akin to a threat it has seen in the past. Perhaps the bad guys targeting you or your organization in this case didn’t use a crypting service, or maybe that service wasn’t any good to begin with.
In either case, antivirus remains a useful — if somewhat antiquated and ineffective – approach to security.  Security is all about layers, and not depending on any one technology or approach to detect or save you from the latest threats. The most important layer in that security defense? You! Most threats succeed because they take advantage of human weaknesses (laziness, apathy, ignorance, etc.), and less because of their sophistication. So, take a few minutes to browse Krebs’s 3 Rules for Online Safety, and my Tools for a Safer PC primer.
Oh, and check out the Wall Street Journal piece that prompted this rant, here.