Can ransomware spread through router?

Ransomware is a type of malware that encrypts files on a device and demands payment in order to decrypt them. There has been an increase in ransomware attacks in recent years, with criminals using more sophisticated techniques to infect devices and extort money from victims.

One question that often comes up is whether ransomware can spread through routers. Routers play a crucial role in home and office networks, connecting multiple devices and allowing them to access the internet. A router infection could potentially allow ransomware to spread rapidly across connected devices.

Can a router get infected with ransomware?

Yes, routers can become infected with ransomware, just like any other device connected to a network. Routers run complex software that can sometimes contain vulnerabilities. If a router has vulnerabilities that are not patched, hackers may be able to exploit them to install ransomware remotely.

In a ransomware attack on a router, the malware essentially hijacks the router software and settings. It can then block access to the router admin console and settings, disable security software, and make other changes to facilitate infection across the network.

There are a few different ways routers can become infected with ransomware:

  • Unpatched vulnerabilities in the router firmware or software
  • Guessed or stolen router admin credentials allowing remote login
  • Malicious ads or pop-ups that load malware onto the router management page
  • Infected USB drives plugged into the router’s USB port

Once ransomware establishes a foothold on the router, it can be very difficult to remove without completely resetting the device.

How does router ransomware work?

Router ransomware works like other ransomware variants, by encrypting files and requiring a ransom payment to decrypt them. However, routers don’t store personal files. Instead, the ransomware blocks access to the router admin console and internet connectivity.

Some examples of what router ransomware may do include:

  • Changing admin account passwords and disabling remote management
  • Reconfiguring DNS settings to redirect traffic through malicious servers
  • Modifying firewall policies to allow incoming malware connections
  • Encrypting router firmware and configuration files
  • Disabling WiFi connectivity or throttling speeds

The ransom note demands a payment, usually in cryptocurrency, in exchange for restoring full access to router settings and connectivity. Since the router manages the entire network, infection effectively cuts off internet access for all connected devices.

Can an infected router spread ransomware?

An infected router can potentially spread ransomware to other devices on the network in some cases. This is because the router has a privileged position managing all traffic between the local network and internet.

Once infected, the router can be manipulated by the ransomware to:

  • Intercept encrypted web traffic and insert malicious scripts into web pages
  • Redirect devices to phishing sites to harvest login credentials
  • Compromise other devices by exploiting vulnerabilities or using stolen passwords
  • Spread across the network via open ports and file shares

However, ransomware would need sophisticated capabilities specifically tailored to spread dynamically from a router. Most router ransomware is focused on locking down the router itself rather than infecting other devices.

Can factory reset remove router ransomware?

Performing a factory reset can potentially remove router ransomware, by restoring the device to a clean state. However, this depends on the particular strain.

In some cases, the ransomware code may remain persisted in the router firmware. Even after a reset, the malware could reinfect the device. Completely eradicating the ransomware may require:

  • Obtaining clean firmware from the vendor and reflashing it
  • Replacing non-rewritable memory chips on the router hardware

For advanced infections, a factory reset alone is not enough. It is better to contact the router manufacturer for guidance to fully eliminate the malware.

How can I prevent router ransomware?

Here are some tips to help prevent ransomware attacks on your router:

  • Update router firmware regularly and enable auto-updates if available
  • Change the admin password from default, use a strong password
  • Disable remote admin access if not needed or restrict to specific IP addresses
  • Turn off unused router functions like USB file sharing
  • Configure router firewall to block unused ports and allow only necessary traffic
  • Setup a guest WiFi network for untrusted devices rather than allowing them on primary network
  • Use a reputable VPN service to encrypt traffic leaving the network
  • Back up your router config regularly in case a factory reset is needed

Implementing strong router security makes it much harder for ransomware to infect your device. Promptly patching vulnerabilities also reduces the risk. Using a layered defense with security software, firewalls, and other measures further minimizes the threat.

What to do if your router is infected with ransomware?

If you suspect your router has been infected with ransomware, take the following steps:

  1. Disconnect the router from power immediately to isolate it and prevent spread
  2. Contact your ISP and inform them your router was compromised
  3. Check router logs for any indicators of compromise from the ransomware
  4. Restore router firmware from a clean backup or by flashing latest from vendor
  5. Reset all router passwords, WiFi SSIDs, and configuration settings
  6. Ensure all devices on network update antivirus software and run scans
  7. Monitor network closely for suspicious activity indicating reinfection

If restoring the router does not fix the issue, you may need to replace it fully. Do not pay the ransom, as it incentivizes and funds criminal actors. Report the attack to authorities to aid investigation efforts.


Routers can become infected with ransomware through various vectors like unpatched firmware vulnerabilities or brute forced login credentials. Once infected, the router can have connectivity disrupted or settings compromised until a ransom is paid. While routers are an attractive target, ransomware is unlikely to spread dynamically from them to other networked devices in most cases.

Prevention is key against router ransomware. Steps like updating firmware, using strong passwords, disabling unused features and implementing firewall rules can help secure your router. Maintaining backups and being prepared to reset or replace compromised routers is important. With proper precautions, the risk of ransomware infection can be greatly reduced.