Story image

MikroTik routers in NZ may be at risk of cryptomining - Symantec

20 Aug 2018

Symantec has been tracking a large-scale coin mining campaign has currently infected about 157,000 MikroTik routers.

Cryptocurrency coinminers are the new ransomware and malicious actors have already pounced on the opportunity to make their fortune.

The coin mining was discovered in August and initially concentrated in Brazil.

However, it soon began infecting routers around the world, and MikroTik routers are available in New Zealand.

Mitigation

MikroTik has already published a patch to address CVE-2018-14847.

Symantec recommends users to install the patch on their routers if they have not done so already.

Users can also consider disabling the following services on their routers, if not required:

  • TELNET
  • SSH
  • FTP
  • WINBOX

These routers are used by many organisations and businesses, including internet service providers.

While MikroTik was prompt in patching CVE-2018-14847, unfortunately, poor patching practices by vendors and users mean that there are plenty of vulnerable routers still out there.

A router post-mortem

At the outset, the compromised router has multiple services running on it.

Interestingly, the infected router had the default web service disabled.

Pointing a browser to the infected router’s port 80 causes it to serve the Coinhive script responsible for coin mining.

But when the infected router is found in between a client sending a request and a server receiving it, this HTML page is only served when there’s an error.

This is because internally the router is configured with a firewall rule that helps serve this malicious HTML page.

Using network address translation (NAT), the firewall rule takes traffic bound to port 80 and redirects it to port 8080.

The router is also configured to run a default proxy server on port 8080 that’s responsible for serving the Coinhive script.

The script below is responsible for performing multiple malicious actions on the router including, but not limited to:

  • Enabling the proxy service
  • Adding the firewall NAT entry
  • Enabling Winbox, FTP, SSH services
  • Disabling the WWW service
  • Scheduling various tasks to remain persistent on the router
  • Adding a backdoor user with the name “ftu” to the FTP group

It’s likely that this script was downloaded using the inbuilt /tool fetch command and run using the /import command.

All the infected MikroTik routers (v6.29 to v6.42) that the Symantec Threat Intelligence encountered were running the Winbox service, which is known to be vulnerable to CVE-2018-14847.

When exploited successfully, this flaw can allow an attacker to bypass authentication and compromise the router.

After the router is compromised, the hackers can load their malicious error page, which is displayed any time a user accessing the internet via the router encounters an HTTP error.

Every time the error page is displayed, the victim is unknowingly mining Monero (XMR) for the hackers.

Why 'right to repair' legislation could be a new lease on life for broken devices
“These companies are profiting at the expense of our environment and our pocketbooks as we become a throw-away society that discards over 6 million tonnes of electronics every year.”
Hands-on review: Huawei Watch GT
I’ve thoroughly enjoyed my time with the Watch GT. It’s converted me from being anti-smartwatch to someone who’s genuinely considering buying one.
How NVIDIA aims to kick-start next-gen gaming
Integrating into game engines new features such as real-time ray tracing can accelerate the development process.
Huawei talks P Series history - and drops hints on the P30
Next week will see the covers come off the new Huawei P30 Series at a special launch event held at the Paris Convention Center.
Hands-on review: Xiaomi’s Mi Mix 3 and the Amazfit Bip
You’ll probably be sad to see another device say ‘farewell’ to the 3.5mm headphone jack. Fortunately though, as mentioned, Xiaomi were kind enough to include an adapter in the box.
How Cognata and NVIDIA enable autonomous vehicle simulation
“Cognata and NVIDIA are creating a robust solution that will efficiently and safely accelerate autonomous vehicles’ market entry."
Kiwis know security is important, but they're not doing much about it
Only 49% of respondents use antivirus software and even fewer – just 19% -  change their passwords regularly.
Instagram: The next big thing in online shopping?
This week Instagram announced a new feature called checkout, which allows users to buy products they find on Instagram.