January 23, 2017 By Douglas Bonderud 2 min read

In August 2016, a group known as the Shadow Brokers began auctioning off what it claimed were National Security Agency (NSA) hacking tools lifted from the spy agency itself. Now these cybercriminals are at it again, this time selling what appears to be a zero-day Windows exploit, which, according to Softpedia, may target the Server Message Block (SMB) function on Windows machines and permit the compromise of sensitive information.

While there’s no hard evidence that the Shadow Brokers actually have this software, the threat is substantial enough to warrant a warning from the U.S. Computer Emergency Readiness Team (US-CERT) for users to address potential SMB issues or, at the very least, update their Windows install.

Real Windows Exploit or Empty Threat?

As noted by Threatpost, this isn’t the first time the Shadow Brokers have dumped Windows exploits onto the web for profit, but they are using new tactics this time around. Instead of offering analysts a small handful of files to verify, these fraudsters are asking for a 750 bitcoin payout upfront, which translates to over $600,000, with only a few screenshots as proof.

While this could point to a bait-and-switch situation, security researcher Jacob Williams suggested that the tools, judging by the screenshots, may have gone through multiple revisions. This lends credence to claims that they’re actually legitimate exploits.

Despite the US-CERT warning, there’s not much in the way of hard and fast detail when it comes to the Windows exploit itself. The screenshots suggest that it centers on the SMB function. US-CERT said that since this function is available on all Windows systems, compromise could mean the loss of sensitive information.

As a precaution, the agency recommended that users and admins disable SMB v1 and block Transmission Control Protocol (TCP) ports 445 and 139, as well as UDP ports 137-138 for all boundary devices. However, the advisory noted that “disabling or blocking SMB may create problems by obstructing access to shared files, data or devices.” This may be a case of the cure being worse than the disease.

Critical Update

It’s worth noting that — so far — there’s no confirmation of any SMB zero-day in Windows, and Microsoft has no reports of unpatched vulnerabilities in the wild. As Threatpost noted, it’s possible that the Shadow Brokers are actually NSA insiders, meaning they could have access to high-level exploits on the cutting edge of software compromise. Still, per the US-CERT warning, there’s no harm in updating Windows 10 to the latest version.

According to TechTarget, Microsoft claimed that the new OS security measures are so effective they may even be able to stop some unpatched zero-day vulnerabilities. Windows 7 users, meanwhile, face “enormous dangers” because of the software’s “long-outdated security architectures.”

The Shadow Brokers are back, selling something they claim is akin to a zero-day Windows exploit kit for big money online. US-CERT agreed that a potential threat exists, but without definitive proof, blocking SMB may offer more problems than protection. An update to the latest version of Windows 10, meanwhile, gives Microsoft a chance to walk the talk and deliver on zero-day defenses.

More from

Change Healthcare discloses $22M ransomware payment

3 min read - UnitedHealth Group CEO Andrew Witty found himself answering questions in front of Congress on May 1 regarding the Change Healthcare ransomware attack that occurred in February. During the hearing, he admitted that his organization paid the attacker's ransomware request. It has been reported that the hacker organization BlackCat, also known as ALPHV, received a payment of $22 million via Bitcoin.Even though they made the ransomware payment, Witty shared that Change Healthcare did not get its data back. This is a…

Phishing kit trends and the top 10 spoofed brands of 2023

4 min read -  The 2024 IBM X-Force Threat Intelligence Index reported that phishing was one of the top initial access vectors observed last year, accounting for 30% of incidents. To carry out their phishing campaigns, attackers often use phishing kits: a collection of tools, resources and scripts that are designed and assembled to ease deployment. Each phishing kit deployment corresponds to a single phishing attack, and a kit could be redeployed many times during a phishing campaign. IBM X-Force has analyzed thousands of…

How I got started: AI security researcher

4 min read - For the enterprise, there’s no escape from deploying AI in some form. Careers focused on AI are proliferating, but one you may not be familiar with is AI security researcher. These AI specialists are cybersecurity professionals who focus on the unique vulnerabilities and threats that arise from the use of AI and machine learning (ML) systems. Their responsibilities vary, but key roles include identifying and analyzing potential security flaws in AI models and developing and testing methods malicious actors could…

Topic updates

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