A zero-day exploit attack is a type of cyber attack that occurs when a hacker exploits a software vulnerability that potentially even the developers are unaware of. The name "zero-day" comes from the fact that once the developer learns of the vulnerability, they have zero days to create a software patch as every second spent could provide hackers with more time to do damage. 

By nature, this type of digital attack is incredibly difficult to defend against since developers realize the vulnerability only after they've been breached. This rush to put out a patch can cause businesses to panic and not address the breach effectively which makes attacks especially dangerous.

In this article, we'll discuss what causes zero day exploits, the usual vulnerability timeline, examples of exploits, and how to protect your business against them.

What Causes Zero-Day Exploit Attacks

Zero-day exploit attacks are tied to hackers finding weaknesses in software or hardware before anyone else realizes that there's something wrong. These vulnerabilities could stem from many issues, including improper security or computer configurations and programming errors. If left unpatched, these vulnerabilities can lead to a gaping hole in your security, inviting cybercriminals to steal your data.

In some instances, software developers may actually know about the existence of a vulnerability but don't yet have a patch in place. In the worst cases, the developers only catch the vulnerability after the customers inform them of identity or information theft.

Typical targets for this type of cyber attack include businesses that store valuable business data such as customer payment information or personal details.

Timeline of a Zero-Day Attack

1. A company's developers create a piece of software unaware that it contains a security vulnerability.
2. A hacker finds this vulnerability before the developer is aware of it or has a chance to put out a patch to address it.
3. The hacker injects malware to exploit the software vulnerability. Once the malware is active, it can steal files and passwords and render computers unusable.
4. The cyber attack is either detected by the developers or the customers.
5. The developers have to race to put out a patch that covers the vulnerability and stops the damage.
6. Users deploy the patch that ends the vulnerability.
   

Examples of Zero-Day Exploits

One of the most high profile examples of a zero-day attack is the Stuxnet Iran attack. This attack in 2010 happened when a self-replicating computer worm called Stuxnet infected industrial computers in Iranian uranium enrichment plants, sabotaging operations in multiple plants. The worm infected the computers through vulnerabilities in Siemens Step7 software, a software that ran on Microsoft Windows. By the time the staff at the plants realized what had happened, the nuclear facilities were rendered unusable.

Another more recent zero-day attack was with Sony Pictures in 2014. The attack led to the release of sensitive corporate data on file-sharing sites. Compromised data included details of upcoming movies, market plans, and senior Sony executives' personal email addresses. The details of the exact vulnerability exploited in the Sony attack still remains unknown.

How to Protect Your Organization From Zero-Day Attacks

Because zero-day exploits stem from unknown vulnerabilities in software, they can be incredibly difficult to detect. It is not impossible however, to proactively take steps to limit and patch existing vulnerabilities to block threats. Here are some common prevention strategies you can use.

1. Always install software updates for Operating Systems, Web browsers, and open source components as soon as they become available from the manufacturer. Most zero-day attacks occur when hackers exploit vulnerabilities in outdated software.
2. Install smart security software. Newer security software can help block threats using databases of past breaches. 
3. Use vulnerability scanning to proactively identify gaps in your defenses and patch them out before hackers can exploit them.
4. Use a web application firewall (WAF). A WAF scans all incoming packets of data in real-time and filters out possible malicious software.
5. Encourage cyber awareness and healthy cyber practices among your employees. Most zero-day exploits originate from human error.
6. Make sure that your business has cloud backups of all essential data. That way, the company can continue operations during a breach.
7. Have an incident response and recovery plan prepared. This can include threat identification, containment, elimination, and recovery.
   

While zero-day attacks can be devastating for any affected business, the likelihood of an attack can be largely reduced through taking precautionary steps to secure your network. As in all aspects of cybersecurity, complacency is the real killer, and assuming that such an attack won’t happen to your business can be a critical mistake down the line.