On June 22, the Necurs botnets — millions spread out on different machines — all awoke from their slumber and began once again to terrorize victims who got in their path. Only exclamations of “It’s alive!” were missing from the news announcements about this reinvigoration.

Necurs Takes Some Time Off

The botnet slept for a few weeks, although researchers weren’t sure why. During that time period, according to Softpedia, there was a drop in the spam emails that contained Locky ransomware attachments. Dridex was also affected — researchers recorded a lower amount of generated spam emails with that banking Trojan attached — despite the fact that this threat typically uses its own botnet for campaigns.

MalwareTech had some thoughts about this resurgence. “The fact that bots will not stop polling the DGA until a C&C server replies with a digitally signed response would suggest that the botmasters are still fully in control of the botnet, or someone else has gotten a hold of the private key,” its blog stated. It seems that the botmasters are back after a brief vacation.

However, they didn’t pick up right where they left off — there are some new elements to the threat. The new campaign focuses on delivering downloaders for Locky via poisoned emails.

Locky had undergone a makeover too. Proofpoint noted that “just prior to the Necurs disruption, Locky authors had introduced new anti-sandboxing and evasion techniques. Those techniques are present in the new campaigns.”

Protecting From the Persistent Threat

The downloader used by Locky is written in JavaScript, so it’s simple to run. Proofpoint described the infection process, stating that if the malicious attachments were opened, they immediately download and install the ransomware via an obfuscated JavaScript document.

Make sure not to open any attachments from suspicious invoices, especially if they have suspicious file names. Necurs frequently leverages attachments with names containing random six-digit strings, Proofpoint noted. While you’re at it, set up your preferences so that any JavaScript files will not automatically run without your approval.

Whatever ransomware variant shows up at your doorstep one day, remember that clicking on something is giving it authority to exist inside your system. By taking care about what exactly gets to live in your cyber environment, you only help yourself.

More from

The Evolution of Antivirus Software to Face Modern Threats

Over the years, endpoint security has evolved from primitive antivirus software to more sophisticated next-generation platforms employing advanced technology and better endpoint detection and response.  Because of the increased threat that modern cyberattacks pose, experts are exploring more elegant ways of keeping data safe from threats.Signature-Based Antivirus SoftwareSignature-based detection is the use of footprints to identify malware. All programs, applications, software and files have a digital footprint. Buried within their code, these digital footprints or signatures are unique to the respective…

How Do Threat Hunters Keep Organizations Safe?

Neil Wyler started his job amid an ongoing cyberattack. As a threat hunter, he helped his client discover that millions of records had been stolen over four months. Even though his client used sophisticated tools, its threat-hunting technology did not detect the attack because the transactions looked normal. But with Wyler’s expertise, he was able to realize that data was leaving the environment as well as entering the system. His efforts saved the company from suffering even more damage and…

The White House on Quantum Encryption and IoT Labels

A recent White House Fact Sheet outlined the current and future U.S. cybersecurity priorities. While most of the topics covered were in line with expectations, others drew more attention. The emphasis on critical infrastructure protection is clearly a top national priority. However, the plan is to create a labeling system for IoT devices, identifying the ones with the highest cybersecurity standards. Few expected that news. The topic of quantum-resistant encryption reveals that such concerns may become a reality sooner than…

Contain Breaches and Gain Visibility With Microsegmentation

Organizations must grapple with challenges from various market forces. Digital transformation, cloud adoption, hybrid work environments and geopolitical and economic challenges all have a part to play. These forces have especially manifested in more significant security threats to expanding IT attack surfaces. Breach containment is essential, and zero trust security principles can be applied to curtail attacks across IT environments, minimizing business disruption proactively. Microsegmentation has emerged as a viable solution through its continuous visualization of workload and device communications…