Imagine an IT manager in Quebec who thinks he has done everything necessary: all Windows systems have received the April 2025 update. However, a few months later, abnormal behavior occurs on the network. An alert is displayed, linked to a vulnerability that has already been fixed. This is exactly what several organizations around the world are currently experiencing. A patch is not always the end of the story.
A flaw fixed, but still exploited
In April 2025, Microsoft released a patch to address a significant vulnerability in a technical component of Windows called CLFS, which stands for “Common Log File System.” This flaw allowed a cybercriminal, once inside a workstation, to take complete control of the system. The problem: some malicious groups, such as Storm-2460, continue to exploit it today, notably using hacking software called PipeMagic.
This malware acts as a gateway. Once installed, it gives access to other even more dangerous tools, such as the RansomEXX ransomware, which blocks company data and demands a ransom to release it. According to several reports, these attacks have targeted companies in Europe, the Middle East, and South America, and there is no indication that North America is immune.
Why is the patch not always enough?
Sometimes patches are not applied everywhere, for example on computers that are rarely used, disconnected from the network, or managed outside the company’s central system. Sometimes the patch is installed but does not take effect until the system is restarted, which may be overlooked in the heat of the moment. Finally, some security software may take some time to recognize new attacks based on these vulnerabilities.
What managers can do
When faced with this type of threat, it is important to do more than just “install the updates.” You need to make sure they have been applied everywhere, that systems have been restarted, and that the network is being actively monitored for suspicious behavior. Activity logs can be checked to see if anything unusual is happening. And if tools such as PipeMagic or RansomEXX are detected, action must be taken immediately.
Just because a patch has been released doesn’t mean that a vulnerability is behind us. Cybercriminals know that some companies are slow to check their infrastructure or forget details such as restarting. For Quebec SMEs, this attack is a reminder that true protection requires vigilance, auditing, and ongoing training.
If you want to check the integrity of your systems or strengthen your update strategy, the specialists at Mon Technicien can help. Several Quebec SMEs already trust us with their IT security.
Source: 01 Net
in your taskbar.