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Since mid-September, a new IoT botnet has grown to massive proportions. Codenamed IoT_reaper (Reaper for this article), researchers estimate its current size at nearly two million infected devices.
According to researchers, the botnet is mainly made up of IP-based security cameras, network video recorders (NVRs), and digital video recorders (DVRs).
Source code is derived based on some characteristics of Mirai botnet
Researchers from Chinese security firm Qihoo 360 Netlab and Israeli security firm Check Point have spotted and analysed the botnet as it continued to grow during the past month.
The new botnet borrows some of the source code from the Mirai IoT malware, which took down the popular security blog KrebsOnSecurity with a massive DDoS attack, ultimately forcing Brian Krebs, the security expert in charge of the blog, to find a new hosting company and seek shelter behind Google Shield for DDoS protection. However, there are also many new dependencies that make the botnet a standalone threat in its own right. It is believed that this new strain called Reaper could be even more virulent than Mirai.
The biggest difference between Reaper and Mirai is its propagation mechanisms. Mirai will scan for open Telnet ports and attempt to log in using a preset list of default or weak credentials. On the other hand, Reaper does not rely on a Telnet scanner, but primarily uses exploits to forcibly take over unpatched devices and add them to its command and control (C&C) infrastructure.
Netlab says that Reaper, at the time of writing, primarily uses a package for nine vulnerabilities: D-Link 1, D-Link 2, Netgear 1, Netgear 2, Linksys, GoAhead, JAWS, Vacron, and AVTECH. Check Point also spotted the botnet attacking MicroTik and TP-Link routers, Synology NAS devices, and Linux servers.
Reaper “baby” botnet is still growing
Netlab experts say the botnet it’s in incipient stages of development, with its operator busy adding as many devices to the fold as possible.
Exploits are added on a regular basis, while the C&C infrastructure expands to accommodate new bots.
Netlab says that it observed over two million infected devices sitting in the botnet’s C&C servers’ queue, waiting to be processed. Just yesterday, only one of the C&C servers was controlling over 10,000 bots.
Tomorrow is the one-year anniversary of the Dyn DDoS attack
The botnet was first spotted on September 13, around one year after experts first found the Mirai IoT malware. Tomorrow will be the one year anniversary of the Dyn DDoS incident, Mirai’s most impactful DDoS attack that brought down a large portion of the Internet across North America and Europe.
Both Check Point and Netlab point out that Reaper did not launch any DDoS attack, as of yet. Nonetheless, Netlab says Reaper comes with a Lua-based execution environment integrated into the malware that allows its operator to deliver modules for various tasks, such as DDoS attacks, traffic proxying, and other.
But Reaper’s Lua core also comes embedded with 100 DNS open resolvers, a functionality that will allow it to carry out DNS amplification attacks with ease.
Only time will tell if this botnet will ever be deployed in live attacks like Mirai, or will be a dud like Hajime.
This week, both the FBI and Europol warned about the dangers of leaving Internet of Things devices exposed online.
Immediate infection countermeasures
By using some tricks, we are able to draw some fairly accurate measurement on the scale of the infection, here are a sample of the numbers.
- Number of vulnerable devices in one c2 queue waiting to be infected : over 2m;
- Infected bots controlled by one c2 in last 7 days: over 20k ;
- Number of daily active bots controlled by one c2 : around 10k for yesterday(October 19) ;
- Number of simultaneous on-line bots controlled by one c2 : around 4k
IoC’s URL Links
IoC – MD5 Hash Values
 IoT_reaper: A Rappid Spreading New IoT Botnet: http://blog.netlab.360.com/iot_reaper-a-rappid-spreading-new-iot-botnet-en/