Recorded Future's "Insikt" threat intelligence research group has linked the Mirai variant IoTroop (aka Reaper) botnet with attacks on the Netherlands financial sector in January 2018.
The existence of IoTroop was first noted by Check Point in October 2017. At that point the botnet had not been used to deliver any known DDoS attacks, and its size was disputed. What was clear, however, was its potential for growth.
In January 2018, the financial services sector in the Netherlands was hit by a number of DDoS attacks. Targets included ABN Amro, Rabobank and Ing; but at that time the source of the attack was unknown.
Insikt researchers now report that at least one these financial services attacks -- and possibly more -- was the first known use of IoTroop to deliver a DDoS attack. "IoTroop is a powerful internet of things (IoT) botnet," reports Insikt, "primarily comprised of compromised home routers, TVs, DVRs, and IP cameras exploiting vulnerabilities in products from major vendors including MikroTik, Ubiquity and GoAhead."
The attack itself was not excessively high by modern standards. "The initial attack was a DNS amplification attack with traffic volumes peaking at 30Gb/s," reports Insikt -- far short of the 1.7Tb/s attack that occurred in February.
If the IoTroop assumption is correct, it is clear the botnet has evolved extensively since its discovery last year. Fortinet's SVP products and solutions reported last month, "the Reaper [IoTroop] exploit was built using a flexible Lua engine and scripts, which means that instead of being limited to the static, pre-programmed attacks of previous exploits, its code can be easily updated on the fly, allowing massive, in-place botnets to run new and more malicious attacks as soon as they become available."
Insikt reports that the malware can use at least a dozen vulnerabilities and can be updated by the attackers as new vulnerabilities are exposed. "Our analysis," it says, "shows the botnet involved in the first company attack was 80% comprised of compromised MikroTik routers with the remaining 20% composed of various IoT devices ranging from vulnerable Apache and IIS web servers to routers from Ubiquity, Cisco and ZyXEL. We also discovered Webcams, TVs and DVRs among the 20% of IoT devices, which included products from major vendors such as MikroTik, GoAhead, Ubiquity, Linksys, TP-Link and Dahua."
This list adds new devices now vulnerable to IoTroop in addition to those noted in the original October 2017 research -- which suggests, says Insikt, "a widespread and rapidly evolving botnet that appears to be leveraging publicly disclosed vulnerabilities in many IoT devices."
Insikt's research shows the January attack was delivered from 139 different countries, showing a widespread targeting of vulnerable IoT devices around the world. More than half of the attacking clients are located in the Russian Federation, Brazil, Ukraine, China and the U.S.; but this probably has no relevance other than popularity of MikroTik devices in those countries.
Insikt believes that its analysis of the January DDoS attacks makes it almost certain that at least one and probably more were delivered by IoTroop; but that the new devices included within the botnet show its continuing evolution. "The similarity in device composition with the IoTroop/Reaper botnet," it says, "suggest IoTroop has evolved to exploit vulnerabilities in additional IoT devices and is likely to continue to do so in the future in order to build up the botnet to facilitate larger DDoS attacks against the financial sector."
The research also found seven IP addresses that it believes are likely to be controllers for the botnet. Insikt urges industry to monitor these addresses for malicious activity since they "are likely to be engaged in aggressive scanning for new vulnerable IoT infrastructure to commandeer as well as be responsible for any Denial of Service, attack commands issued to the botnet clients."
Protecting consumer IoT devices is less simple, since consumers notoriously adopt an unpack, plug and play approach to new devices. Nevertheless, Recorded Future urges all users to immediately change default manufacturer passwords, to patch firmware wherever possible and required, to invest in a VPN for devices that have remote access (such as IP cameras), and -- perhaps less easily for consumers -- to disable unnecessary services such as Telnet.
Related: Remotely Exploitable Vulnerability Discovered in MikroTik's RouterOS