MAY 4 Stealer Log: 89,770 Credentials Exposed (Sep 2023)

89,770 Credentials in 3,885 Log Files: The MAY 4 Stealer Log Campaign

On September 26, 2023, a Telegram user uploaded a stealer log collection named "MAY 4 - 3885 LOGS" exposing 89,770 U.S. endpoint credentials in plaintext. The "3885 LOGS" designation reveals the file's structure: not a single exfiltration event, but a compilation of 3,885 individual session log files harvested by information-stealing malware and bundled into a single distributable package. Simultaneously, a companion upload -- "MAY 4 - 3818 LOGS" -- added another 86,478 records. In a single day, the MAY 4 campaign distributed more than 176,000 plaintext U.S. credentials through the same Telegram channel.

MAY 4 (September 26, 2023): Breach Summary

• Records Exposed: 89,770
• Data Types: Plaintext credentials (email addresses, passwords, endpoint URLs, API hosts)
• Breach Type: Stealer log
• Country Affected: United States
• Date Leaked: September 26, 2023

What "MAY 4" Likely Means

The "MAY 4" designation in the file name likely refers to a campaign name, a malware variant identifier, or an operation codename used by the operator. Stealer log distributors often use internal naming conventions for different infection campaigns or malware deployment waves -- sometimes referencing the date the original malware was first deployed, sometimes referencing specific tooling or victim segments. The September 26, 2023 upload date indicates that by the time these logs reached Telegram, the underlying malware had already been running for an extended period, accumulating credentials from thousands of infected devices before the operator chose to release them in bulk. The 3,885 individual log files suggest a sustained collection period rather than a single-day harvest.

The Risk of Bulk Stealer Log Releases

When an operator releases 89,770 credentials in a single Telegram upload, the risk profile differs from the daily drip of smaller stealer log campaigns. Large bulk releases tend to attract immediate attention from the underground ecosystem -- threat actors who monitor Telegram channels for exactly this kind of high-value batch. Within hours, a 90K-record plaintext credential file can be re-distributed across multiple channels, integrated into credential-stuffing tool databases, and sold in portions on dark web forums. The credential-stuffing attack surface for any individual victim expands rapidly as the batch spreads. For organizations with employees or customers whose credentials appear in the MAY 4 logs, the exposure window began on September 26, 2023 and has continued expanding ever since.

A 176K+ Day: MAY 4's Two-Upload Release Strategy

The simultaneous release of two MAY 4 batches -- 89,770 and 86,478 records -- on the same day reflects a distribution strategy commonly used by sophisticated stealer log operators. Splitting a large collection into two near-equal portions can serve multiple purposes: evading file-size limits on certain Telegram configurations, creating two distinct downloads that channel subscribers must separately obtain (incentivizing engagement), or simply reflecting the underlying file organization of the original harvested collection. The combined 176,248-record release makes September 26, 2023 one of the larger single-day stealer log distribution events indexed in the HEROIC breach database.

Check If Your Credentials Were Exposed

HEROIC's free breach scanner searches more than 400 billion exposed records, including the MAY 4 stealer log campaign and thousands of other breach sources. If your email address or endpoint credentials appeared in this or the companion 86,478-record MAY 4 release, HEROIC can tell you. Run a free scan at HEROIC.com to check your current exposure.