Security researchers have identified two new threats — Hide ‘N Seek (HNS) and Android Debug Bridge miner (ADB) — which are designed to compromise consumer devices to create Internet of Things (IoT) botnets.
When Fortinet initially tracked HNS in early 2018, the malware was using complex, peer-to-peer communication to compromise routers, IP cameras and DVRs. Over the past several months, the creators added new capabilities. Now, HNS “targets cross-platform database solutions and smart home devices,” according to a July 2018 Fortinet threat report.
Trend Micro discovered a new exploit in early July that uses the Android Debug Bridge (ADB) command line utility, which automatically listens on port 5555, to create a mining botnet. While the threat is currently limited in scope because ADB is turned off by default, Shodan, a search engine for IoT devices, turned up 48,000 exploitable devices.
Mirai-Based Attacks Persist Despite Rising Awareness of IoT Risks
Fortinet noted that HNS uses open source Mirai code to quickly adapt, leveraging a combination of copied code and creative inspiration to add features like code persistence after a reboot. The latest version of HNS also uses nine separate exploits to infect IoT devices.
The ADB threat, meanwhile, is seemingly linked to the Satori version of Mirai and was likely created by the same author, according to a July 2018 IBM X-Force threat advisory. This means that despite increased awareness of IoT threats, Mirai-based attacks are still in development — and still succeeding.
How Can Companies Mitigate the Risk of IoT Botnets?
To protect IoT environments from threats like Mirai, IBM experts recommend changing all default passwords and establishing an incident response team to “conduct regular gap analyses to monitor the data generated by connected devices.”
Organizations should also be aware of emerging Telnet trends in IoT botnets. After the Mirai attack, for example, the use of Telnet attack source rose by 140 percent. IBM X-Force researchers suggest limiting Telent use in corporate environments or replacing it with a stronger alternative like Secure Shell (SSH).