A malicious IP blocklist, or an IP blacklist, is a list of IP addresses linked to undesirable internet activities such as spamming and distributing malware. These lists are used to filter and block traffic from a range of cyber threats, safeguarding servers, email systems, and other networked digital infrastructures. An IP blacklist is integral in the proactive protection of a wide variety of digital threats, including hacking attempts and brute force attacks, from a network. Whether you manage a business WiFi network, run a WordPress website or server, or own a home internet connection, implementing an IP blocklist is essential to protect your infrastructure from the latest threats and attacks.

Malicious IP blacklists are compiled through a number of methods. Many are based on crowdsourced intelligence from platforms that allow users to report specific IP addresses associated with various types of cyber threats, such as phishing, spamming, and other malicious activity. Other sources include industry groups in sectors such as finance, healthcare, and technology. Some are even compiled by individual organizations or software manufacturers.

Blocking the Bad Guys: Leveraging a Malicious IP Blocklist

Once a suspicious or dangerous IP address is identified, it is added to the appropriate malicious IP blacklist. This process is then referenced by firewalls, email servers, and other software to filter or block traffic from the relevant IP address. In the case of a business, it could prevent customers from being able to access or transact with their company online. Fingerprint’s suite of Smart Signals includes out-of-the-box support for IP blocklists, as well as browser bot detection, VPN detection, and Android tampering detection, which can help flag unusual or suspicious behaviors and alert security teams to potential incidents.