Microsoft 365 Message Encryption Can Leak Sensitive Info
The default email encryption used in Microsoft Office's cloud version is leaky, which the company acknowledged but said it wouldn't fix.
Stay secure with the latest email security updates, best practices, and threat alerts to protect your inbox and sensitive information.
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Background for this topic.
Email is a system for exchanging digital messages, typically using mail servers and clients over a network. In security, it includes both the messages and the accounts, servers, domains, and authentication mechanisms that handle them. Email commonly carries phishing links, malicious attachments, and fraudulent requests for payments or credentials; compromised accounts can also be used to impersonate trusted people and conduct further attacks.
Defenses include filtering and malware scanning, phishing-resistant multifactor authentication, careful handling of links and attachments, and monitoring for unusual login or sending activity. Domain controls such as SPF, DKIM, and DMARC help receiving systems detect messages that are forged or sent without authorization, while encryption protects message contents in transit or at rest when correctly implemented. Security teams should preserve relevant headers and mailbox activity so suspicious messages can be investigated, removed, and used to identify affected accounts and other recipients.
The default email encryption used in Microsoft Office's cloud version is leaky, which the company acknowledged but said it wouldn't fix.
The campaign uses a combination of tactics and a common JavaScript obfuscation technique to fool both end users and email security scanners to steal credentials.
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