Why Understanding Zero-Day Exploits Matter
 

Let’s face it, the potential for being the first organization to be hit with the next creative zero-day cyberattack strikes fear into the heart of every CISO and IT security professional. Knowing that the potential impact of such malware could mean millions in lost productivity and/or data, as well as the incalculable impact on your company’s reputation if it hits the evening news as well, is enough to make every cybersecurity professional want to carefully understand what makes zero-day exploits so impactful.

What is a Zero Day Exploit?

According to Wikipedia, a zero-day threat is:

 “A zero-day (also known as 0-day) vulnerability is a computer-software vulnerability that is unknown to those who would be interested in mitigating the vulnerability (including the vendor of the target software). Until the vulnerability is mitigated, hackers can exploit it to adversely affect computer programs, data, additional computers or a network. An exploit directed at a zero-day is called a zero-day exploit, or zero-day attack.

In the jargon of computer security, "Day Zero" is the day on which the interested party (presumably the vendor of the targeted system) learns of the vulnerability. Up until that day, the vulnerability is known as a zero-day vulnerability. Similarly, an exploitable bug that has been known for thirty days would be called a 30-day vulnerability. Once the vendor learns of the vulnerability, the vendor will usually create patches or advise workarounds to mitigate it.”

It turns out that zero-day exploits have a shelf life of as long as it takes for the industry (read security vendors) to discover it, forensically diagnose how it works and then apply a fix to their solutions in the way of a software patch, a signature update or an update to their cloud services. 

The bad news is that there is a “vulnerability window” that can sometimes be hours or even days. Since it only takes minutes, or even seconds, for any zero-day exploit to wreak havoc to your organization’s productivity, profitability and reputation, you will need to ensure you are protected adequately with the appropriate cyber threat prevention solution.

How Can There Be So Many New Zero Day Exploits?

The reason zero-day exploits seem to be so prevalent is the concept of Polymorphic variants. According to TechTarget, next generation malware actually mutates in order to act like a new zero-day exploit and evade signature-based cyber prevention solutions. The article goes on to state that:

“Polymorphic code typically uses a mutation engine that accompanies the underlying malicious code. The mutation engine doesn't change the underlying code; instead, the engine generates new decryption routines for the code. The mutation engine can also alter the file names of the polymorphic code. As a result, each time the code is installed on a new device or system, the mutation engine generates a brand new decryption routine.

A polymorphic virus includes an encrypted payload and a mutation engine. The encryption hides the malicious payload from scanners and threat detection software, which are left to identify the virus by its decryption routine. Once the virus is installed on a target, the payload is decrypted and it infects the system; the mutation engine randomly creates a new decryption routine so that when the virus moves to the next target, it appears to be a different file to scanners.”

Zero Day Malware Prevention

The only way to ensure zero-day cyber treat prevention is with a signature-less engine that searches for hidden opcode instructions inside data files, regardless of code flow (encrypted, encoded) or size. The engine should also analyze active content (e.g. Microsoft Office macros, embedded JavaScript) through next-gen de-obfuscation capabilities and an advanced set of heuristics to reveal malicious files.