MTProto protocol was not directly broken, the weakness

[samiaseo222]

However, under specific conditions—such as poor network transitions, insecure proxies, or outdated app versions—the session management mechanism failed to properly expire and rotate tokens. Hackers exploited this flaw by intercepting these session tokens through man-in-the-middle (MITM) attacks on compromised networks. Once the tokens were captured, attackers could use them to request user metadata, including last seen times, contact lists (in some cases), and phone number verification statuses. Although the in session management effectively bypassed some of Telegram’s trust boundaries.

This breach demonstrated a fundamental truth about security: vulnerabilities don’t always lie in the encryption algorithms themselves but often in the way systems are implemented and configured. The brazil telegram data breach showcased the classic principle of insecure session persistence, a problem well-known in the cybersecurity community but difficult to fully eliminate in complex distributed systems like Telegram. Scope and Scale of the Leak While Telegram did not disclose the exact number of users affected by the breach, cybersecurity analysts estimate that metadata for over 40 million accounts was potentially scraped and stored by malicious actors.

This includes: Usernames and Telegram IDs Associated phone numbers Session device identifiers (e.g., Android, iOS, desktop) Timestamps of recent activity Region and language preferences Presence in public groups or channels One of the most concerning aspects of the breach was its geopolitical dimension. Many of the leaked user accounts appeared to belong to users in politically sensitive regions, including Iran, Russia, and certain Middle Eastern countries where Telegram serves as a critical platform for political activism and uncensored communication.