The call coming from inside the house is the most dangerous one. Unlike a hack from an outside threat actor, insider threats come from individuals who have legitimate access to systems and data within an organization. Employees, contractors, and business associates can all do the most damage because they operate from a position of trust. This allows insider threats to evade traditional security measures until it is too late.
Network engineers play a critical role in defending organizational infrastructure. Their vantage point allows them to detect subtle anomalies that others might miss. As a network engineer, have you considered the following six insider threat signals to your system?
1. Unusual Logins
One of the clearest early warning signs of an insider threat is abnormal login behavior. This can include:
- Logins on weekends or outside of working hours (for instance, a login at 3 am on a Sunday)
- Unrecognized devices or geolocations
- Repeated failed login attempts
- Successful login after a series of failed efforts
An employee working remotely, or someone who forgot their password and then successfully reset it, can cause these one-off events. If they become a pattern, they should be investigated. Engineers can set up alerts for logins at strange times, from new locations, or anything else that seems like an anomaly in access.
2. Accessing Sensitive Data
Every employee should only access the data necessary to perform their job duties. If you spot any of the following out of the ordinary, you may have an insider threat:
- Downloads of large amounts of data
- Missing files
- Financial or confidential files are being accessed repeatedly
- Information from sensitive departments is being viewed by an employee outside of that department
One solution to restrict excessive access to sensitive data may be implementing zero-trust architecture across the board. Zero-trust architecture allows system users to access only the data and tasks they need. When it comes to hackers, it can significantly limit the damage that they can do to systems.
3. Use of Unauthorized Devices or Applications
Shadow IT, or the use of unsanctioned hardware or software, presents a significant security risk to any company. Insider threats often use unauthorized tools to exfiltrate data or bypass monitoring systems. You might spot USB storage devices being used in restricted environments or unauthorized scripts running in the background. Non-approved VPNs or other remote desktop software are another common red flag. A vigilant network engineer should monitor for unauthorized ports, new applications on the network, and any device attempting to connect outside of the organization’s security controls.
4. Bypassing Security Measures
Engineers should be alert to employees who frequently attempt to override or ignore established security protocols. While it might be a clever employee trying to create their own shortcut, it can open the door to serious vulnerabilities within your network. Don’t let laziness or a quest for convenience unravel company security systems. Disabling endpoint protection software or creating backdoors leads to more harm than good. Likewise, employees who share login credentials or turn off multi-factor authentication not only put their own information at risk, but also compromise company-wide cybersecurity measures.
5. Changes to Behavior
HR and IT can work hand in hand to detect insider threat signals in many instances. A network engineer who receives a notice from HR, or who spots unusual behavior in an employee, may be able to identify and prevent a serious breach. A sudden decline in job performance or dissatisfaction with company leadership can be a signal to limit an employee’s network access. Likewise, make sure to offboard employees thoroughly by changing passwords, ensuring company devices are returned, and restricting their access to company emails, chats, client registers, and systems. Some of the most dangerous hacks have been spearheaded by disgruntled ex-employees, as seen in these remote access hacks into water filtration systems.
6. Anomalous Network Traffic or Data Transfers
Excessive or abnormal outbound traffic, especially to non-corporate IPs or cloud storage providers, is a serious warning sign. A network engineer should watch out for:
- Unusually high bandwidth usage from a single endpoint
- Uploads to Dropbox, Google Drive, or other cloud platforms during off-hours
- Encrypted file transfers to external IP addresses
- Spikes in outbound data, especially from employees who have given notice or who otherwise may have restricted access
Implementing SIEM (Security Information and Event Management) systems can correlate this activity with user identity to flag suspicious patterns.
Cybersecurity defense starts with awareness
Insider threats are uniquely dangerous because they arise from trusted users operating within intact network defenses. Detecting them requires more than firewalls and antivirus software. Network engineers are in a unique position to monitor system design, recognize suspicious patterns, and use tools like user and entity behavior analytics (UEBA) to spot trouble early.
Turning signals into action
No single warning sign is proof of an insider threat, but a combination should never be ignored. By knowing these six signals and monitoring for them consistently, network engineers can help prevent costly breaches, protect sensitive data, and maintain the integrity of organizational systems. Vigilance against insider threats is everyone’s responsibility — but it often starts with the engineers who see the traffic first.
About NetworkTigers
NetworkTigers is the leader in the secondary market for Grade A, seller-refurbished networking equipment. Founded in January 1996 as Andover Consulting Group, which built and re-architected data centers for Fortune 500 firms, NetworkTigers provides consulting and network equipment to global governmental agencies, Fortune 2000, and healthcare companies. www.networktigers.com.
