What Are Zero Day Vulnerabilities & How to Combat Them

Zero-Day vulnerabilities are among the most prominent threats facing businesses, given the challenge of quickly identifying and remediating their weaknesses. Not only is it lucrative for threat actors and their sympathizers to identify and publish zero-days before they are patched, for which there are additional complications related to privilege or confidentiality, but the scope and impact of their exploitation can be far-reaching and impossible to clean up quickly. The victims of the Log4j, GoAnywhere, or Microsoft zero-day attacks can attest to this reality. (The Rock)

What is a Zero Day Vulnerability?

A zero-day vulnerability is an unintended software or operating system defect that can create a security hole. Cybercriminals exploit these holes to enter your systems and networks to corrupt files, distribute emails using company addresses, take control of your systems, or steal everything from money to IP to sensitive personal data.

The term “zero-day” means a software flaw has yet to be discovered by the software’s development team; consequently, there’s no patch or update available for complete zero-day attack mitigation. When the flaw is finally discovered, the developer has zero days to fix the vulnerability before criminals can exploit it, leaving users unprotected and at significant risk.

When cybercriminals discover software flaws, they write malicious code—malware—which they use to exploit your systems to their benefit. According to the Software Engineering Institute, over 90% of security attacks target software flaws and defects, meaning virtually no one is immune.

While there are no infallible zero-day threat protections, there are actionable steps to protect yourself the best you can.

1. Institute a Least Privilege Model Within Your Organization

Users should only have access to resources necessary to perform their work and nothing more. This strategy is critical in a zero-day threat protection plan. Should cybercriminals exploit an undetected flaw and gain access to an employee’s credentials, they would only have access to limited information. By minimizing exposure, you’re minimizing the possible threat.

2. Conduct Regular Staff Training on How to Spot Phishing Emails

If this sounds like a broken record, there’s a reason why. The latest reports indicate nearly 70% of cybercriminal behavior is launched via email. And zero-day attacks are no different. Phishing schemes are the ultimate launching pad for cybercriminal activity. Training exercises detailing how to spot phishing and social engineering scams and how to mitigate compromised communications properly is critical to your organization’s safety.

3. Engage With a Managed Detection and Response Service

The days of using only antivirus software or a basic “black box” monitoring device for cybersecurity are over. With today’s sophisticated and savvy cybercriminal threats, the best zero-day threat protection means enlisting an advanced cybersecurity provider for a Managed Detection and Response (MDR) service. MDR provides real-time monitoring and response. So, if your organization is attacked or even breached, your security provider can respond immediately. A top-tier MDR service powered by a fully-staffed, 24/7/365 Security Operations Center is a necessary defense against zero-day attacks.

4. Maintain Stand-Alone Backups and Keep Accurate, Up-To-Date Logs

A strong backup plan can be your organization’s salvation when protecting against zero-day exploits. Keep multiple backups separate from your network to minimize the impact and potential losses should a zero-day attack occur. It’s also essential to know where backups are stored, when and what information is backed up, and who is responsible for maintaining the backups themselves. This includes all recordkeeping associated with data preservation. Establishing a backup protocol with set backup schedules is a simple and effective means of preserving data if an incident occurs.

5. Regularly Review and Practice Your Incident Response Plan

Too many companies put themselves at risk by creating incident response (IR) plans and placing them on the shelf to gather dust. Beyond that, only 45% of organizations have an IR plan. IR plans should evolve and change with your organization and be tested in real-world scenarios, known as tabletop exercises. In zero-day scenarios, preparedness is your best weapon. Plan down to the last detail, then see how your team responds when faced with a team of ethical hackers supplied by your cybersecurity partner. What you learn during practice sessions will better equip your team when faced with a real incident.