Last updated at Thu, 16 Mar 2023 17:18:06 GMT

Data exfiltration is an unauthorized movement or transfer of data occurring on an organization’s network. This can occur when a malicious actor gains access to a corporation’s network with the intention of stealing or leaking data.

Data exfiltration can also be carried out by inside actors moving data outside of the network accidentally, by uploading corporate files to their personal cloud – or deliberately to leak information that harms the organization.

Identifying this cyber risk is integral to securing your organization’s network.

Of course, attackers use multiple methods

Some use phishing scams to trick users into inputting personal login information into spoofed domains so that they can use the appropriate credentials to infiltrate the network. Once on to the network, the malicious actor can send the files they were searching for outside of their network using remote desktop, SSH, etc.

Another method? Ignoring security controls of a network. For example, employees may download unauthorized software for ease of use, but unintentionally allow a third party to gain access to sensitive information that was not meant to leave the network. People may use personal accounts and devices for work related tasks just because it’s easy. A malicious inside actor can also circumvent security controls to leak information outside of the network.

With many organizations moving to a hybrid model of work, it’s more important than ever to prevent data exfiltration, intended or unintended. This can be done by educating your employees of appropriate conduct when it comes to data usage and data sharing within and outside of your network. Education about common attack vectors attackers may use to steal their credentials will also help your employees keep your network secure. Additionally, education around what devices can access your network will make it easier to monitor whether a data breach is about to occur. Finally, assigning certain privileges based on employee functions will help.

Being able to detect data exfiltration is incredibly important for an organization’s environment and essential to your organization’s security posture. One of our new detections, Anomalous Data Transfer, provides you with the visibility into possible occurrences of data exfiltration within your network.

Rapid7s approach for detecting Anomalous Data Transfers

Anomalous Data Transfer is an InsightIDR detection which utilizes network flow data, produced by the Insight Network Sensor, to identify and mark unusual transfers of data and behavior. The detection identifies anomalously large transfers of data sent by assets out of a network, and outputs data exfiltration alerts.

The model dynamically derives a baseline for each asset based on its active periods over 30 days, and each hour, will output network activity that is anomalously high as compared to that baseline as a candidate for further investigation. This process effectively acts as a filter, reducing millions of network connections into a few candidate alerts to bring to the attention of a security analyst.

Further contextual information is included in each candidate alert to help a security team make informed decisions about how to investigate the possible occurrence of data exfiltration.

The user has the ability to tune exceptions for which anomalous data transfer alerts are shown by going into Managed Detections. The user can tune exception rules for Anomalous Data Transfer with the following attributes: Organization, Certificate, and Source IP/Subnet. This allows for the analysts to focus on alerts that are well tailored to their organization’s environment.