Thursday, June 13, 2024

Necurs, the world’s largest spam botnet with nearly 5 million infected bots launching DDoS attacks

Necurs is a malware that is mainly known for sending large spams contains nearly 5 million infected bots, of which one million active each day.

Its not only Spam bot, but peace of malware that is composed of a main bot module Necurs usefulness is separated over a few modules that are stacked on tainted PCs continuously, just when required.

According to security researchers from threat intelligence company Anubis Networks, As indicated by the typical port 80 interchanges, a Necurs tainted framework was speaking with an arrangement of IPs on an alternate port utilizing, what had all the earmarks of being, an alternate convention.

The DDoS capability was added almost six months ago via Necurs’ new Proxy module.

The accompanying picture demonstrates a case of this system activity.

An underlying investigation of the module arranged it as an on-request intermediary server that could malicious traffic through infected hosts, by means of HTTP, SOCKSv4, and SOCKSv5 intermediary conventions.

Every DDoS record will easily breakable by A Necurs DDoS attack

In the event that Necurs could ever choose to utilize its bots for a DDoS assault, the size of such an assault would be past some other DDoS assault we’ve found before.

For most of its lifespan, the authors of the Necurs botnet have used it to send spam from infected hosts, usually carrying the Dridex banking trojan, and more recently the Locky ransomware.

“The proxy/DDoS module is quite old,” said MalwareTech, a security researcher that has tracked Necurs’ evolution for years. “I imagine it was put in as a potential revenue stream but then they found there was more money in spam.”

Outside a higher revenue stream the Necurs gang stands to earn from spam, we must also take into consideration other reasons why it’s highly unlikely that we’re going to see DDoS attacks from Necurs.

Necurs creators have put time and cash into building up an expert, very much oiled digital cyber-crime machine. There is no motivation to chance their unfaltering income stream only for running a DDoS-for-contract benefit from which they have just to lose.

Scientifically, it looks bad to pulverize three income streams (Dridex, Locky, and rentable spamming administration) only for making and supporting a DDoS booter benefit.

According to threat intelligence company Anubis Networks,

It seemed to be a simple SOCKS/HTTP proxy module, but as we looked at the commands the bot would accept from the C2 we realized that there was an additional command, that would cause the bot to start making HTTP or UDP requests to an arbitrary target in an endless loop, in a way that could only be explained as a DDOS attack. This is particularly interesting considering the size of the Necurs botnets (the largest one, where this module was being loaded, has over 1 million active infections each 24 hours, A botnet this big can likely produce a very powerfull DDOS attack.

Start/initialization Module by Anubis Networks,

Once the module is loaded by the bot, it performs the following initialization actions:

  1. Parses the parameters and stores them in an internal list of C2 addresses;
  2. Fills a memory structure (see botsettings struct definition below) with:
  3. The BotID – Generated through gathering unique system characteristics;
  4. The internal IP address – Obtained by checking the outbound sockets IP address when connecting to;
  5. The external IP address – Obtained trough HTTP from or;
  6. The available bandwidth – Obtained by measuring the download speed of the Windows 7 Service Pack 1 file from microsoft;
  7. The (socks/http) proxy service port – The port of the service listening on a random port above 1024;
  8. Checks if the system is behind NAT – By checking if the outbound socket IP is not a local address and that it matches the external IP;
  9. If the system is not behind NAT, the bot starts a SOCKS/HTTP proxy service listening on a random port above 1024.

Also Read :


Latest articles

CISA Warns of Scammers Impersonating as CISA Employees

The Cybersecurity and Infrastructure Security Agency (CISA) has issued a warning about a surge...

Microsoft Windows Ntqueryinformationtoken Flaw Let Attackers Escalate Privileges

Microsoft has disclosed a critical vulnerability identified as CVE-2024-30088.With a CVSS score of 8.8, this flaw affects Microsoft...

256,000+ Publicly Exposed Windows Servers Vulnerable to MSMQ RCE Flaw

Cybersecurity watchdog Shadowserver has identified 256,000+ publicly exposed servers vulnerable to a critical Remote...

Indian National Jailed For Hacked Servers Of Company That Fired Him

An Indian national was sentenced to two years and eight months in jail for...

JetBrains Warns of GitHub Plugin that Exposes Access Tokens

A critical vulnerability (CVE-2024-37051) in the JetBrains GitHub plugin for IntelliJ-based IDEs (2023.1 and...

Critical Flaw In Apple Ecosystems Let Attackers Gain Unauthorized Access

Hackers go for Apple due to its massive user base along with rich customers,...

Hackers Exploiting Linux SSH Services to Deploy Malware

SSH and RDP provide remote access to server machines (Linux and Windows respectively) for...
BALAJI is an Ex-Security Researcher (Threat Research Labs) at Comodo Cybersecurity. Editor-in-Chief & Co-Founder - Cyber Security News & GBHackers On Security.

Free Webinar

API Vulnerability Scanning

71% of the internet traffic comes from APIs so APIs have become soft targets for hackers.Securing APIs is a simple workflow provided you find API specific vulnerabilities and protect them.In the upcoming webinar, join Vivek Gopalan, VP of Products at Indusface as he takes you through the fundamentals of API vulnerability scanning..
Key takeaways include:

  • Scan API endpoints for OWASP API Top 10 vulnerabilities
  • Perform API penetration testing for business logic vulnerabilities
  • Prioritize the most critical vulnerabilities with AcuRisQ
  • Workflow automation for this entire process

Related Articles