The best IPS solutions take advantage of threat intelligence and automatically turn it into protection. This gives security operations teams more control over users and applications and reduces time spent reacting to alarms.
An IPS detects attacks by mirroring data flows and either reports them as an attack or interworks with the firewall to block them. IPS can also be customized to provide security controls unique to each enterprise.
What is an IPS?
Understanding the difference between an IDS vs IPS is essential because, unlike network IDS systems, which are only effective at scanning networks for threats and need human intervention to respond once a threat is spotted, an IPS actively monitors network traffic for any signs of malicious activity. It uses either a database of known attacks and their signatures or machine learning to recognize new threats emerging and then takes action automatically.
IPSs are generally deployed inline between the firewall and network endpoints, where they intercept the communication path. They can block suspicious packets and scrub dangerous parts of existing traffic to keep hackers from spreading their attacks across the enterprise or redirecting them to a honeypot. They also log incidents and generate reports for SOC teams to review.
There are several different types of IPSs:
Policy-based IPSs use access control policies set by the security team and then flag anything that violates those rules, such as when an unauthorized user tries to connect to a host. Signature-based IPSs use established attack patterns to identify a breach, and anomaly-based IPSs sample data randomly and compare it against pre-established performance levels, identifying anything out of the ordinary.
Signature-based IPSs require frequent updates to detect current and emerging threats. In contrast, anomaly-based IPSs may produce false positives that disrupt legitimate traffic.
What is an IDS?
An IDS is a network monitor that looks for current and past traffic anomalies. The system establishes a baseline for everyday activity, including bandwidth, protocols, ports, and communicating IP addresses. Anomaly-based detection compares current traffic to that baseline and detects deviations that may indicate a security breach. These systems are often rule-based, but more and more IDS vendors are turning to machine learning for this function. Anomaly-based detection can also be more effective at catching new cyberattacks that would evade signature-based detection, such as zero-day attacks that exploit software vulnerabilities before developers have had time to issue patches.
Once an anomaly is detected, the IPS can take action to protect the network from the threat. The IPS can shut down the source of the attack, block communications with the source, and remove any malware from internal networks or connected devices. It can also reconfigure firewalls and other security tools to prevent the attack from occurring again. Typically, IPSs log detected incidents and generate reports for security teams to analyze.
The problem with IDSs, however, is that they can generate a lot of false alarms because they are constantly scanning and comparing current and past activity against known threats. In some cases, these false alerts interrupt legitimate activities. For this reason, some organizations choose to forgo using IDSs and rely solely on more advanced protections like a firewall or an SIEM solution.
What is the difference between an IPS and an IDS?
IDS solutions are typically network-based and monitor a network’s activity via sensors placed throughout the IT infrastructure. They can detect abnormal behavior that could indicate the presence of an attack and alert the IT team to the issue.
However, IDS solutions must be tuned to specific environments and policies, or they can result in false positives that interrupt business operations and leave the organization vulnerable to attackers. IDS solutions can also not take action on an alert and must pass the incident to a human or another system to decide how best to respond, which can leave a threat untouched and unchecked.
An IPS system takes the monitoring and detection capabilities of an IDS and adds a proactive element to the mix by actively denying threats from entering the network. This is done by dropping suspicious packets, preventing connections from being established, or terminating existing connections in case of a potential threat. For an IPS to accurately and effectively block attacks, it must have a well-defined set of rules and a regularly updated threat profile. A common way to achieve this is through signature-based detection, which looks for known attack behavior patterns, such as file hashes, byte sequences characteristic of malicious code, or even email subject lines commonly used in phishing campaigns.
Which is better for my business?
Ultimately, it depends on your business‘s needs. An IPS system is more comprehensive than an IDS solution in preventing threats from entering the network instead of simply detecting them after an attack. It can take various automated actions and rules during an incident, such as blocking a specific source, closing connections, or resetting connections to thwart attacks. This gives it a leg up on IDS solutions that only alert you to an incident and leave it up to you to remediate the threat manually.
An IPS system works in real time and inspects each packet of data that moves through your network. It uses signature-based and statistical anomaly-based detection to respond to intrusions promptly. Signature-based detection compares the features of malicious code with an existing database of known threats such as worms, ransomware, and viruses. Statistical anomaly detection compares your network’s performance to a pre-established baseline to detect unusual activity on your network.
IDS and IPS systems are hands-off once set up but can be prone to false positives if the parameters aren’t adequately defined. However, they can be a great way to improve your information security in an automated manner and help you meet many compliance requirements without hiring additional staff.
