US CERT update on Home Network Security
What is home network security?
Home network security refers to the protection of a network that connects devices to each other and to the internet within a home. Whether it’s staying in touch with friends and family, paying your bills electronically, or teleworking, the internet enables us to accomplish tasks more efficiently and conveniently from the comfort of our own homes. However, as we increasingly embed technology into our daily lives, the risk of security issues also increases. As a result, it’s imperative that home users understand and remain vigilant about the risks of being connected to the internet and the importance of properly securing home networks and systems.
Why should I care?
Many home users share two common misconceptions about the security of their networks.
They believe that their home network is too small to be at risk of a cyberattack.
They believe that their devices are “secure enough” right out of the box.
Most attacks are not personal in nature and can occur on any type of network—big or small, home or business. If a network connects to the internet, it is inherently more vulnerable and susceptible to outside threats.
Many internet-enabled consumer products come preconfigured with factory-issued settings, including default usernames and passwords. Many people leave these unchanged, creating opportunities for malicious cyber actors to gain unauthorized access to information, install malicious software (malware), and cause other problems.
How do I improve the security of my home network?
By following some of the simple but effective mitigation techniques below, you can significantly reduce the attack surface of your home network and make it more difficult for a malicious cyber actor to launch a successful attack.
Update your software regularly. Regular software updates are one of the most effective steps you can take to improve the overall cybersecurity posture of your home networks and systems. Besides adding new features and functionality, software updates often include critical patches and security fixes for newly discovered threats and vulnerabilities. Most modern software applications will automatically check for newly released updates. If automated updates are not available, consider purchasing a software program that identifies and centrally manages all installed software updates.
Remove unnecessary services and software. Disable all unnecessary services to reduce the attack surface of your network and devices, including your router. Unused or unwanted services and software can create security holes on a device’s system, which could lead to an increased attack surface of your network environment. This is especially true with new computer systems on which vendors will often pre-install a large number of trial software and applications—referred to as “bloatware”—that users may not find useful. National Cybersecurity and Communications Integration Center (NCCIC) recommends that you research and remove any software or services that are not being used regularly.
Adjust factory-default configurations on software and hardware. Many software and hardware products come “out of the box” with overly permissive factory-default configurations intended to make them user-friendly and reduce the troubleshooting time for customer service. Unfortunately, these default configurations are not geared towards security. Leaving them enabled after the installation may create more avenues for an attacker to exploit. Users should take steps to harden the default configuration parameters to reduce vulnerabilities and protect against intrusions.
Run up-to-date antivirus software. A reputable antivirus software application is an important protective measure against known malicious threats. It can automatically detect, quarantine, and remove various types of malware, such as viruses, worms, and ransomware. Many antivirus solutions are extremely easy to install and intuitive to use. NCCIC recommends that all computers and mobile devices on your home network run antivirus software. Additionally, be sure to enable automatic virus definition updates to ensure maximum protection against the latest threats. Note: Because detection relies on signatures—known patterns that can identify code as malware—even the best antivirus will not provide adequate protections against new and advanced threats, such as zero-day exploits and polymorphic viruses.
Install a network firewall. Install a firewall at the boundary of your home network to defend against external threats. A firewall can block malicious traffic from entering your home network and alert you to potentially dangerous activity. When properly configured, it can also serve as a barrier for internal threats, preventing unwanted or malicious software from reaching out to the internet. Most wireless routers come with a configurable, built-in network firewall that includes additional features—such as access controls, web-filtering, and denial-of-service (DoS) defense—that you can tailor to fit your networking environment. Keep in mind that some firewall features, including the firewall itself, may be turned off by default. Ensuring that your firewall is on and all the settings are properly configured will strengthen the network security of your network. Note: Your Internet Service Provider (ISP) may be able to help you determine whether your firewall has the most appropriate settings for your particular equipment and environment.
Install firewalls on network devices. In addition to a network firewall, consider installing a firewall on all computers connected to your network. Often referred to as host- or software-based, these firewalls inspect and filter a computer’s inbound and outbound network traffic based on a predetermined policy or set of rules. Most modern Windows and Linux operating systems come with a built-in, customizable, and feature-rich firewall. Additionally, most vendors bundle their antivirus software with additional security features such as parental controls, email protection, and malicious websites blocking.
Regularly back up your data. Make and store—using either external media or a cloud-based service—regular backup copies of all valuable information residing on your device. Consider using a third-party backup application, which can simplify and automate the process. Be sure to encrypt your backup to protect the confidentiality and integrity of your information. Data backups are crucial to minimize the impact if that data is lost, corrupted, infected, or stolen.
Enable wireless security. Follow the steps below to increase the security of your wireless router. Note: Consult your router’s instruction manual or contact your ISP for specific instructions on how to change a particular setting on your device.
Use the strongest encryption protocol available. NCCIC recommends using the Wi-Fi Protected Access 2 (WPA2) Personal Advanced Encryption Standard (AES) and Temporary Key Integrity Protocol (TKIP), which is currently the most secure router configuration available for home use. It incorporates the Advanced Encryption Standard (AES) and is capable of using cryptographic keys of 128, 192, and 256 bits. This standard has been approved by the National Institute of Standards and Technology (NIST).
Change the router’s default administrator password. Most network devices, including wireless access points, are pre-configured with default administrator passwords to simplify setup. These default credentials are not secure—they may be readily available on the internet, or may even be physically labeled on the router itself. Changing your router’s administrator password will help protect it from an attack using default credentials.
Change the default SSID. Sometimes referred to as the “network name,” a service set identifier (SSID) is a unique name that identifies a particular wireless local area network (WLAN). All wireless devices on a WLAN must use the same SSID to communicate with each other. Because the device’s default SSID typically identifies the manufacturer or the actual device, an attacker can use this to identify the device and exploit any of its known vulnerabilities. Make your SSID unique and do not tie it to your identity or location—information that makes it easier for the attacker to identify your home network.
Disable WPS. Wi-Fi Protected Setup (WPS) provides simplified mechanisms for a wireless device to join a Wi-Fi network without the need to enter the wireless network password. However, a design flaw in the WPS specification for PIN authentication significantly reduces the time required for a cyber attacker to brute force an entire PIN, because it informs them when the first half of the eight-digit PIN is correct. Many routers lack a proper lockout policy after a certain number of failed attempts to guess the PIN, making a brute-force attack much more likely to occur. See Wi-Fi Protected Setup (WPS) Vulnerable to Brute-Force Attack.
Reduce wireless signal strength. Your Wi-Fi signal frequently propagates beyond the perimeters of your home. This extended emission allows eavesdropping by intruders outside your network perimeter. Therefore, carefully consider antenna placement, antenna type, and transmission power levels. By experimenting with your router placement and signal strength levels, you can decrease the transmitting coverage of your Wi-Fi network, thus reducing this risk of compromise. Note: While this reduces your risk, a motivated attacker may still be able to intercept a signal that has limited coverage.
Turn the network off when not in use. While it may be impractical to turn the Wi-Fi signal off and on frequently, consider disabling it during travel or extended periods when you will not need to be online. Additionally, many routers offer the option to configure a wireless schedule that will automatically disable the Wi-Fi at specified times. When your Wi-Fi is disabled, you prevent outside attackers from being able to exploit your home network.
Disable UPnP when not needed. Universal Plug and Play (UPnP) is a handy feature that allows networked devices to seamlessly discover and establish communication with each other on the network. However, though the UPnP feature eases initial network configuration, it is also a security risk. Recent large-scale network attacks prove that malware within your network can use UPnP to bypass your router’s firewall, allow attackers to take control of your devices remotely, and spread malware to other devices. You should therefore disable UPnP unless you have a specific need for it.
Upgrade firmware. Check your router manufacturer’s website to ensure you are running the latest firmware version. Firmware updates enhance product performance, fix flaws, and address security vulnerabilities. Note: Some routers have the option to turn on automatic updates.
Disable remote management. Most routers offer the option to view and modify their settings over the internet. Turn this feature off to guard against unauthorized individuals accessing and changing your router’s configuration.
Monitor for unknown device connections. Use your router manufacturer’s website to monitor for unauthorized devices joining or attempting to join your network. Also see the manufacturer’s website for tips on how to prevent unauthorized devices from connecting to your network.
Mitigate Email Threats. Phishing emails continue to be one of the most common initial attack vectors employed by for malware delivery and credential harvesting. Attacking the human element—considered the weakest component in every network—continues to be extremely effective. To infect a system, the attacker simply has to persuade a user to click on a link or open an attachment. The good news is that there are many indicators that you can use to quickly identify a phishing email. The best defense against these attacks is to become an educated and cautious user and familiarize yourself with the most common elements of a phishing attack. Below are some common indicators of a phishing email.
Suspicious Sender’s Address. Pay attention to the sender’s email address. It may imitate a legitimate business. With only few characters altered or omitted, cybercriminals will often use an email address that closely resembles one from a reputable company.
Generic Greetings and Signature. Both a generic greeting—such as “Dear Valued Customer” or “Sir/Ma’am”—and a lack of contact information in the signature block are strong indicators of a phishing email. A trusted organization will normally address you by name and provide their contact information.
Spoofed hyperlinks. Hover your cursor over any links in the body of the email. The links not matching the text that appears when hovering over them should raise a red flag. Additionally, the use of a URL shortening service to hide the true destination of the link should also raise a red flag.
Spelling and Layout. Poor grammar and sentence structure, misspellings, and inconsistent formatting are other indicators of a possible phishing attempt. Reputable institutions have dedicated personnel that produce, verify, and proofread customer correspondence.
Suspicious Attachments. An unsolicited email requesting a user download and open an attachment is a common delivery mechanism for malware. A cybercriminal may use a false sense of urgency or importance to help persuade a user to download or open an attachment without examining it first.
Improve Password Security. Weak or stolen passwords have been linked to a large number of recent data breaches and cyber attacks, and passwords continue to be one of the most vulnerable cyber defenses.
Consider using a password manager. A password manager is a software that can help you generate, store, encrypt, and retrieve unique and complex login credentials for all your accounts, effectively eliminating the need to remember or write down passwords.
Make passwords long and complex. The most effective aspect of a strong password is length. You should therefore consider using the longest password or passphrase permissible. For example, “Passwd4mymiemale!” would be a strong password because it has 17 characters. It also includes the upper and lowercase letters, numbers, and special characters often required by password systems. You may need to try different variations of a passphrase—some applications limit the length of passwords, some do not accept spaces or certain special characters. Avoid easily guessable password, for example, common phrases, famous quotations, song lyrics, sequential keyboard combinations—such as “qwerty” or “123456”—or words found in the dictionary.
Create a unique password for each account. Do not use the same password with multiple accounts. This way, if one of your accounts is compromised, the attacker will not be able to breach any other of your accounts.
Never use personal information. Avoid using your personal information such as your name, pet’s name, birth date, phone number, or any other publicly available information.