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A specially crafted S/MIME signed message can trigger a use-after-free during PKCS#7 signature verification in OpenSSL. The important detail is that message validation itself becomes part of the attack surface. In Microsoft 365 environments, S/MIME remains present in regulated and executive workflows where signed messages are trusted by default. Many organizations focus on attachment scanning but rarely review certificate-based email handling paths. Inventory systems that process S/MIME content automatically. openssl-library.org/news/sec… #microsoft365 #Cybersec #InfoSec

Microsoft temporarily disabled 73 GitHub repositories after password-stealing malware was pushed into trusted Microsoft code projects. The concern isn't just malware delivery. Compromised developer credentials often become cloud identity problems. In Microsoft 365 environments, attackers frequently pivot from developer access into Entra-connected resources. Many organizations first spot this during identity investigations. Review sign-ins tied to privileged developer accounts. bleepingcomputer.com/news/se… #microsoft365 #Cybersec #InfoSec

Spam is often the first visible sign of account compromise. Once a mailbox is abused to send spam, the impact extends beyond cleanup. In Microsoft 365 environments, compromised accounts are frequently used to distribute phishing or spam from trusted domains. Many organizations first notice this through outbound mail anomalies. Review unusual sending patterns alongside Entra ID sign-in activity. guardiandigital.com/resource… #microsoft365 #Cybersec #InfoSec

University phishing campaigns continue succeeding despite user awareness efforts. Awareness alone rarely stops credential theft. In Microsoft 365 environments, successful attacks are usually a combination of convincing lures and routine business workflows. Most security teams recognize this only after correlating email and sign-in telemetry. guardiandigital.com/resource… #microsoft365 #CyberAttack #InfoSec

Ransomware groups are increasingly operating like service providers, selling infrastructure, access, and tooling to affiliates. This shortens the path from initial access to operational impact. For Microsoft 365 tenants, compromised credentials can quickly become mailbox access, internal reconnaissance, and persistence. Many organizations discover the activity only after reviewing audit and sign-in data. csoonline.com/article/418151… #microsoft365 #InfoSec #Cybersec

The worm successfully leveraged reused passwords and common enterprise misconfigurations. That should sound familiar. Microsoft 365 investigations regularly uncover shared accounts, legacy service credentials, and access paths that survived multiple security projects. Most tenants have at least one exception that no one wants to touch. Review conditional access exclusions periodically. csoonline.com/article/418192… #microsoft365 #TechSecurity #InfoSec

The FBI reported that 30% of phishing emails make it through existing protections and get opened by users. That means email filtering isn't the final control. In Microsoft 365 environments, credential theft often starts with a single successful click. Many compromises begin as a routine user report in Outlook. Review Entra ID sign-in activity after phishing events. guardiandigital.com/resource… #microsoft365 #Cybersec #InfoSec

Microsoft has released security updates addressing more than 200 vulnerabilities across Windows, SharePoint, and other widely deployed products and services, making this one of the company's most significant patch cycles to date. Several issues affecting Microsoft-hosted cloud services, including Microsoft 365, were resolved by Microsoft directly and do not require customer intervention. Given the widespread use of Microsoft's technology across enterprise environments, Guardian Digital is issuing a global advisory to all clients. Guardian Digital's Threat Intelligence Team expects the volume of newly disclosed vulnerabilities requiring timely remediation to continue growing as advanced automated discovery and agentic scanning technologies become more effective. We will continue to monitor emerging threats and provide targeted notifications to organizations affected by critical and high-severity security vulnerabilities. msrc.microsoft.com/update-gu…

Researchers observed AI utility posts on underground forums jump from 38 to 1,486 in just a few months. The key takeaway is not sophistication. It's accessibility. In Microsoft 365 environments, more operators can now build convincing campaigns without deep technical expertise. Credential theft remains effective because it blends into normal user behavior. Regular review of Conditional Access exclusions still pays dividends. csoonline.com/article/418151… #microsoft365 #CyberDefense #CyberThreats

Several university phishing incidents began with a single compromised account. One account can become an attack platform. In Microsoft 365, attackers commonly abuse legitimate mailboxes to bypass reputation controls and reach internal users. Internal-to-internal phishing remains one of the most recognizable patterns in investigations. Check for unusual sending behavior from user accounts. guardiandigital.com/resource… #microsoft365 #CyberDefense #TechSecurity

Researchers found that free, locally run AI models were sufficient to drive the attack. The takeaway is operational, not theoretical. Attackers don't always need advanced tooling when common weaknesses remain available. Microsoft 365 environments frequently contain dormant accounts, stale permissions, and forgotten exceptions. Those small gaps tend to accumulate over time. csoonline.com/article/418192… #microsoft365 #CyberThreats #Cybersec

Strong email encryption often requires certificate management, key exchange, or external key control. The security benefit comes with operational overhead. Microsoft 365 administrators know that adoption usually depends on how easy the process is for users. Even well-designed controls fail when deployment complexity gets ignored. guardiandigital.com/resource… #microsoft365 #InfoSec #TechSecurity

Ransomware activity increasingly starts with account access rather than an infected attachment. The initial compromise is often a phishing link and stolen credentials. Attackers spend time inside the tenant before taking action. Many organizations only reconstruct the timeline after reviewing audit logs. guardiandigital.com/resource… #microsoft365 #CyberAttack #InfoSec

The prototype adapted its attack path based on what it found on each system. That reduces the need for manual attacker decision-making. In Microsoft 365, compromised accounts are often used to discover new opportunities through mailbox access, Teams conversations, and directory visibility. Many organizations only see the full scope after reviewing audit logs. csoonline.com/article/418192… #microsoft365 #CyberDefense #InfoSec

University phishing attacks frequently rely on trusted institutional branding. That trust reduces hesitation before clicking. In Microsoft 365 environments, attackers often mimic HR, registrar, finance, or IT communications to increase engagement rates. Administrators see similar patterns across industries. Review which messages generate the highest user interaction. guardiandigital.com/resource… #microsoft365 #CyberThreats #Cybersec

URL shorteners, redirect chains, and lookalike domains make malicious links harder to spot. A quick hover check is no longer enough in many cases. Attackers routinely mimic Microsoft 365 workflows and branding. Most admins have seen users click links that appeared legitimate at first glance. guardiandigital.com/resource… #microsoft365 #CyberDefense #Cybersec

Stolen and jailbroken AI service accounts are now among the most common offerings on ransomware forums. This expands attacker access to tools that can automate reconnaissance and content generation. In Microsoft 365 environments, automation often accelerates phishing, credential harvesting, and post-compromise activity. Attackers increasingly scale operations the same way administrators do. csoonline.com/article/418151… #microsoft365 #Cybersec #TechSecurity

The incident highlights how attackers increasingly target automated trust decisions instead of passwords themselves. When a system can approve identity-related actions, that system becomes part of the attack surface. Microsoft 365 defenders see similar patterns with OAuth consent abuse, token misuse, and delegated access. The challenge is rarely the login. It's what happens after trust is granted. Periodic reviews of app permissions and privileged access still pay dividends. techcrunch.com/2026/06/03/in… #microsoft365 #CyberThreats #TechSecurity

Some secure email features focus on access controls rather than true message encryption. That changes who can access the content, not necessarily how it is protected. In Microsoft 365 environments, this distinction often surfaces during compliance reviews and data handling assessments. Terminology causes more confusion than technology. guardiandigital.com/resource… #microsoft365 #CyberDefense #CyberThreats

Researchers demonstrated an AI-powered worm that can autonomously exploit known vulnerabilities and common misconfigurations. The important detail: it doesn't require zero-days to spread. In Microsoft 365 environments, the same principle applies when attackers chain weak credentials, excessive permissions, and overlooked access paths. Most incidents still start with something defenders already knew about. Review Entra ID sign-in anomalies regularly. csoonline.com/article/418192… #microsoft365 #Cybersec #InfoSec