June 13, 2016 By Larry Loeb 2 min read

Proofpoint recently noticed a disturbance in the ransomware force: The Necurs botnet, once one of the largest known botnets, has gone strangely quiet. It used to pump out hundreds of millions of malware-laden emails around the net, among other malicious actions such as distributed denial-of-service (DDoS) attacks.

Necurs is a P2P hybrid botnet that enables communication between infected computers and nodes that function as command-and-control (C&C) servers. The botnet has a domain generation algorithm that allows those infected machines to find a new C&C server should one go down. However, they have not been successful in this endeavor since the shutdown.

The Necurs Botnet Goes Dark

Anubis Networks was the first to observe the botnet’s inactivity on June 1. Millions of bots suddenly went silent, causing major disruptions in Dridex and Locky ransomware campaigns.

Anubis also discovered that an infected Necurs system would connect to a sinkhole only until the bot had found a C&C server to connect with. However, if the bot is somehow disconnected from that server, it might communicate with the sinkhole again.

Interestingly, the last time that Necurs went quiet for this long was in the fall of 2015, when a member of the Dridex gang was arrested in Cyprus, Softpedia reported.

What Does the Future Hold?

Will the Necurs botnet rise from the dead to deal electronic spam upon the unsuspecting masses once more? Proofpoint is doubtful because, although it’s not the first outage of its kind, “available data suggest that it involved a significant and ongoing failure of the C&C infrastructure behind the botnet.” That kind of damage could be hard to remedy.

Necurs needs these C&C servers to organize itself. Luckily, it seems that security researchers will be able to find indications if it does manage to acquire that necessary infrastructure, giving organizations warning as to the possible ransomware resurgence.

Though the email campaigns of Dridex and Locky are still out there, one can only hope the current trickle of Necurs-generated malware doesn’t turn into a flood in the future.

More from

What does resilience in the cyber world look like in 2025 and beyond?

6 min read -  Back in 2021, we ran a series called “A Journey in Organizational Resilience.” These issues of this series remain applicable today and, in many cases, are more important than ever, given the rapid changes of the last few years. But the term "resilience" can be difficult to define, and when we define it, we may limit its scope, missing the big picture.In the age of generative artificial intelligence (gen AI), the prevalence of breach data from infostealers and the near-constant…

Airplane cybersecurity: Past, present, future

4 min read - With most aviation processes now digitized, airlines and the aviation industry as a whole must prioritize cybersecurity. If a cyber criminal launches an attack that affects a system involved in aviation — either an airline’s system or a third-party vendor — the entire process, from safety to passenger comfort, may be impacted.To improve security in the aviation industry, the FAA recently proposed new rules to tighten cybersecurity on airplanes. These rules would “protect the equipment, systems and networks of transport…

Protecting your digital assets from non-human identity attacks

4 min read - Untethered data accessibility and workflow automation are now foundational elements of most digital infrastructures. With the right applications and protocols in place, businesses no longer need to feel restricted by their lack of manpower or technical capabilities — machines are now filling those gaps.The use of non-human identities (NHIs) to power business-critical applications — especially those used in cloud computing environments or when facilitating service-to-service connections — has opened the doors for seamless operational efficiency. Unfortunately, these doors aren’t the…

Topic updates

Get email updates and stay ahead of the latest threats to the security landscape, thought leadership and research.
Subscribe today