Data breaches are one of the top concerns for today’s organizations. The costs of these breaches continue to increase, with the average global cost of a single breach hovering at $4.35 million. Beyond the financial consequences of a breach, network security is also hugely important for any business because an attack can compromise the trust of your customers.

60 percent of small companies go out of business within six months of falling victim to a data security threat or cyber attack. With your business’s financial security and future on the line, organizations of all sizes must have measures in place to monitor suspicious network activity.


What Constitutes Suspicious Network Activity?

Suspicious network activity can refer to several behaviors involving abnormal access patterns, database activities, file changes, and other out-of-the-ordinary actions that can indicate an attack or data breach. 

It is important to recognize these activities because it can help pinpoint the source and nature of the breach, allowing you to act quickly to correct the security threat and minimize damage. Here are some of the most common examples of suspicious activity:

  • Database activity: Abnormal database activity can be caused by either internal or external attacks, and the crucial signs to watch for include changes in your users, changes in permissions, and unusual data content growth.
  • Account abuse: The abuse of privileged accounts is one of the most common signs of an insider attack, and symptoms to watch for are modified audit trails, sharing of account access, and the accessing of sensitive information without a need.
  • User access: Strange changes in user access are generally signs that an external party, such as a hacker, is trying to gain access to your network using a user’s credentials. Behaviors you'll notice include users accessing accounts at odd hours, accessing remotely, having multiple failed attempts to log in, and discrepancies between a user and a particular device.
  • File changes: Configuration changes to files—including replacement, modifications, file additions, and deletion—is a classic sign of a data breach because it indicates somebody has infiltrated your network and is trying not to be discovered.
  • Unexpected network behavior: This is another sign of an attempted infiltration from outside sources. You should be on the lookout for traffic with odd origins or targets, protocol violations, inexplicable changes in network performance, and unauthorized scans.
  • Unauthorized port access: Although this may be a result of an insider accident, unsanctioned port access can also indicate a malware attack or that files have already been stolen.
  • Changes detected by end-users: For small organizations with fewer detection and security measures in place, end users may be the first to notice the effects of suspicious activity. Changes may include excessive pop-ups, odd anti-virus notifications, slow devices or networks, and unauthorized toolbars.

Is Suspicious Network Activity the Same for All Organizations?

Though there are common signs of suspicious activity, the specifics will vary within industries and organizations of different sizes. The reason for these differences is that different hackers have different reasons for attempting to breach a network.

Related Read: Challenges of Infrastructure Security

For example, a hacker attempting to breach the database of a large hospital system will have different motivations than a hacker seeking to breach the credit card data of a small business. 

A small business may notice user abuse or abnormal database activities as hackers try to gain access to personal or cardholder information, whereas a financial institution may be more prone to account abuse, unauthorized port access, and malware attacks designed to steal social security and financial data.

Private organizations may be susceptible to advanced persistent threats (APTs), which are defined as multi-phase attacks on an organization's network. Though often aimed at governmental organizations, APTs can affect small and medium-sized businesses as well.


Combatting Suspicious Network Activity

As with many problems, the key to combating suspicious network activity is prevention, and this involves having a solid organization-wide security strategy. Here are a few items that should be included in any comprehensive data security approach:

  • Malware protection
  • Strong password policies
  • Regular review of network alerts, error reports, performance, and traffic
  • Installing firewalls
  • Training end users to detect and report suspicious activity
  • File integrity monitoring
  • Regular risk assessments
  • Incident and failure response strategies


Network Security Tools

We discussed some of the ways you can detect and combat suspicious network activity in the previous section. Let’s take a closer look at some of the network security tools you can use to identify and mitigate the severity of network threats. 

  • IDS (Intrusion Detection System): An IDS helps alert your staff of potentially malicious activity in your network. However, it simply detects and alerts your IT department, this tool does not take action to prevent or remediate an attack. 
  • IPS (Intrusion Prevention System): An IPS is similar to an IDS, but in addition to identifying a potential breach, this tool can also take action to prevent an attack by blocking the suspicious activity in question. 
  • DLP (Data Loss Prevention): A DLP tool can help your organization ensure that your confidential information is secure and protected from unauthorized release or alteration. 
  • SIEM (Security Incident and Event Management): SIEMs encompass a variety of tools and solutions that monitor and control network activity. When you’re using a SIEM your team can identify breaches in-progress. This real-time detection helps with quick response times. 
  • NBAD (Network Behavior Anomaly Detection): An NBAD system works by first identifying “normal” system behavior. With this in place, the system can identify abnormal behavior, even if it is not a sign of a specific, known threat. 

Detect Suspicious Network Activity with File Integrity Monitoring 

One of the fastest-growing security trends for data protection is file integrity monitoring (FIM). FIM automates the monitoring of your important files, systems, networks, and more. With the right FIM software, you can constantly monitor for and detect suspicious changes in real-time. As mentioned in Creating a File Integrity Monitoring Strategy, common aspects of a FIM strategy can include clearly defined roles, proper documentation, and well-thought-out planning.

A reliable FIM tool and strategy will not only enhance your data security but will also help you achieve compliance with security standards like PCI DSS, which explicitly states the need for file integrity monitoring.

Any organization entrusted with customer data must take security seriously because it’s not just information that’s on the line: data breaches aren't just expensive, but they can also tarnish an organization’s reputation. 

Unfortunately, hackers and malicious parties are always upping the ante in terms of new techniques and tactics to breach networks, but file integrity monitoring and having a great data protection policy in place can protect your organization, your data, your reputation, and your customers.

To learn more about File Integrity Monitoring, download the Definitive Guide to File Integrity Monitoring today. 

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Lauren Yacono
Post by Lauren Yacono
December 29, 2022
Lauren is an IU graduate and Chicagoland-based Marketing Specialist.

About Cimcor

Cimcor’s File Integrity Monitoring solution, CimTrak, helps enterprise IT and security teams secure critical assets and simplify compliance. Easily identify, prohibit, and remediate unknown or unauthorized changes in real-time