Printer Security: Stop Attacks

TL;DR

Office printers are often overlooked security risks. They can be hacked to steal data, disrupt operations, or provide a backdoor into your network. This guide shows you how attackers do it and what simple steps you can take to protect yourself.

How Attackers Target Printers

Attackers exploit vulnerabilities in printer software, firmware, and network configurations. Common methods include:

• Direct Network Access: Printers connected directly to the internet or a local network without proper security measures are vulnerable.
• Exploiting Firmware Bugs: Older printers often have unpatched vulnerabilities in their firmware.
• Man-in-the-Middle Attacks: Intercepting communication between the printer and your computer.
• Malicious Documents: Sending specially crafted documents that exploit printer software flaws.

Protecting Your Printers – Step by Step

1. Update Printer Firmware Regularly
   • Check the manufacturer’s website for updates. Most manufacturers provide a way to download and install firmware updates directly on their support pages.
   • Enable automatic updates if available.
2. Change Default Credentials

   Printers come with default usernames and passwords that attackers know. Change these immediately.

   • Access the printer’s web interface (usually by typing its IP address into a web browser).
   • Navigate to the administration or security settings.
   • Create strong, unique passwords for all accounts.
3. Disable Unnecessary Services

   Many printers have services you don’t need enabled. Disabling them reduces your attack surface.

   • Access the printer’s web interface.
   • Look for options like FTP, Telnet, or LPD. Disable these if they aren’t used.
4. Network Segmentation

   Isolate your printers on a separate network segment (VLAN) to limit the damage an attacker can cause.

   • Configure your router or firewall to create a dedicated VLAN for printers.
   • Restrict communication between the printer VLAN and other parts of your network.
5. Enable Secure Printing Protocols

   Use protocols like IPsec or TLS to encrypt communication between computers and printers.

   • Configure your printer drivers to use secure printing protocols. This is often found in the advanced settings of the driver properties.
6. Monitor Printer Activity

   Keep an eye on what your printers are doing.

   • Check printer logs for unusual activity, such as large print jobs or access from unknown IP addresses.
   • Some printers offer email alerts for specific events.
7. Restrict Access Control

   Limit who can use the printer and what they can do.

   • Use printer access control lists (ACLs) to restrict printing permissions based on user or group.
   • Implement authentication requirements for print jobs.
8. Consider a cyber security audit

   A professional cyber security assessment can identify vulnerabilities you might miss.

Checking Your Printer’s IP Address

You need the printer’s IP address to access its web interface. Here are a few ways to find it:

• Printer Control Panel: Many printers display their IP address on their control panel or in a network settings menu.
• Network Scanner: Use a network scanner tool (e.g., Angry IP Scanner) to scan your network for connected devices and identify the printer’s IP address.
• Router Interface: Log into your router’s web interface and look at the list of connected devices. The printer should be listed there with its IP address.