Digital Event Horizon
Microsoft has announced its intention to deprecate RC4, a cryptographic algorithm that has been widely used in various applications, including Active Directory authentication. The move comes after over a decade of devastating hacks that exploited the weaknesses in RC4, which have left numerous organizations and individuals vulnerable to attacks.
Micrsoft will deprecate RC4 due to its vulnerabilities. RC4, a widely used algorithm, has been plagued by critical weaknesses since its development in 1987. The weaknesses in RC4 have led to devastating hacks and breaches in the past. Organizations must take immediate action to identify and replace RC4-based authentication protocols. Micrsoft is providing tools to help organizations identify problematic RC4 usage.
In a move that is being hailed as a major victory for cybersecurity enthusiasts around the world, Microsoft has announced its intention to deprecate RC4, a cryptographic algorithm that has been widely used in various applications, including Active Directory authentication. The decision comes after over a decade of devastating hacks that exploited the weaknesses in RC4, which have left numerous organizations and individuals vulnerable to attacks.
RC4, short for Rivest Cipher 4, is a stream cipher that was first developed by mathematician and cryptographer Ron Rivest of RSA Security in 1987. Despite its widespread use, RC4 has been plagued by several critical vulnerabilities, including the notorious Kerberoasting attack, which was first discovered in 2014. This attack exploits a weakness in RC4's implementation in certain authentication protocols, allowing hackers to obtain sensitive information without needing to crack the password.
The impact of these weaknesses cannot be overstated. Last year's breach of health giant Ascension, which involved the theft of medical records from over 5.6 million patients, is just one example of the devastating consequences of RC4's vulnerabilities. The breach, which was attributed to hackers exploiting a vulnerability in Active Directory authentication using RC4, highlights the severity of the problem and the need for organizations to take immediate action to address it.
Despite its widespread use, RC4 has been considered insecure for many years. In 1994, a researcher demonstrated a cryptographic attack that significantly weakened the security provided by RC4. Since then, numerous other vulnerabilities have been discovered, including a particularly devastating one that was discovered in 2011. This vulnerability, known as Pseudorandom Number Generator (PRNG) attacks, allows hackers to predict the output of the PRNG algorithm used by RC4, effectively rendering it useless.
In light of these findings, Microsoft has announced its intention to deprecate RC4, a move that is being hailed as a major victory for cybersecurity enthusiasts around the world. The decision will see RC4 disabled by default on all supported Windows versions, except in cases where administrators explicitly configure an account or domain controller to use it.
The impact of this change cannot be overstated. Organizations that rely on RC4-based authentication protocols will need to take immediate action to address the vulnerabilities associated with these protocols. This includes identifying any systems within their networks that still use RC4 and implementing alternative authentication protocols, such as AES-SHA1.
To help organizations identify problematic RC4 usage, Microsoft is introducing several tools, including an update to KDC logs that will track requests and responses made using RC4 when performing requests through Kerberos. The company is also providing new PowerShell scripts that can be used to sift through security event logs and pinpoint any instances of RC4 usage.
The deprecation of RC4 marks a significant turning point in the fight against cyber attacks. As more organizations move away from RC4-based authentication protocols, the risk of vulnerabilities being exploited decreases significantly. The tools provided by Microsoft will help ensure that organizations are better equipped to identify and address these risks, reducing the likelihood of another devastating breach like the one suffered by Ascension.
In conclusion, the deprecation of RC4 is a major victory for cybersecurity enthusiasts around the world. By taking steps to address the vulnerabilities associated with this algorithm, Microsoft has helped to reduce the risk of cyber attacks and protect organizations from the devastating consequences of these breaches.
Related Information:
https://www.digitaleventhorizon.com/articles/Microwave-Ovens-The-Unlikely-Culprits-Behind-the-Global-Cybersecurity-Crisis-deh.shtml
https://arstechnica.com/security/2025/12/microsoft-will-finally-kill-obsolete-cipher-that-has-wreaked-decades-of-havoc/
https://m365admin.handsontek.net/legacy-tls-cipher-suites-will-deprecated-m365-services-october-20-2025/
Published: Mon Dec 15 16:06:47 2025 by llama3.2 3B Q4_K_M
