Researchers Link MARCH 12 537 LOGS to 5,580 Stolen Credentials on Telegram

HEROIC Analysts Discover 5,580 Records in MARCH 12 537 LOGS Telegram Stealer Dump

In April 2023, HEROIC analysts uncovered a stealer log file uploaded to Telegram under the name MARCH 12 - 537 LOGS. The dataset contained 5,580 compromised records bundled from 537 individual infostealer log files. Each record included an email address, a plaintext password, and the URL of a service the victim had been authenticated to when the malware ran on their device. The upload date of April 15, 2023 indicates this data moved from infected machines to criminal distribution channels within weeks of collection.

Why Bundled Stealer Logs Are So Valuable to Attackers

A bundle of 537 individual log files, like this MARCH 12 dataset, represents 537 separate device infections. Each infection is a unique victim with a unique set of credentials. Attackers value these bundles because they deliver large volumes of verified, ready-to-use credentials tied to specific services via the included URLs. Unlike hashed password databases that require cracking, the plaintext passwords here are immediately usable. Threat actors load these credentials into automated tools and run them against banking sites, email providers, and corporate portals in credential stuffing campaigns that can compromise thousands of accounts in hours.

What Was Exposed in This Stealer Log Bundle

HEROIC confirmed the following data types were present across all 537 logs in this dataset:

• Email Addresses
• Plaintext Passwords
• URLs (identifying the exact services each victim used)

Why This Exposure Continues to Create Risk

The MARCH 12 537 LOGS dataset was distributed in April 2023, but that does not mean the risk has passed. Stealer log datasets are archived, re-shared, and recombined into new dumps for years after their initial release. Any user whose credentials appeared in this file and who has not since changed their passwords remains exposed to account takeover, identity theft, credential stuffing, and financial fraud. People who recieve suspicious login alerts or unusual account activity on services they use regularly should consider checking whether their email was included in this or related dumps.

How Infostealer Bundles Like MARCH 12 Are Assembled

The 537 individual logs in this bundle each originated from a seperate device infection. Infostealer malware typically occured its initial infection through a phishing email, a fake crack or keygen download, or a malicious browser extension. Once running on a device, it extracts saved passwords from browsers, harvests active authentication cookies, and records which URLs the victim recently visited. Operators then aggregate hundreds of these individual logs into named bundles and upload them to Telegram channels as promotional samples or paid content. The MARCH 12 label likely indicates the collection date of the raw logs before bundling and distribution in April.

Check If Your Information Was Included

HEROIC's free dark web scanner checks your email address against 400 billion+ records, including Telegram stealer log bundles like MARCH 12 - 537 LOGS. If your credentials were among the 5,580 records exposed in this dump or in any other breach database, HEROIC will alert you so you can act quickly. Visit heroic.com to run your free scan right now.