Monster Cloud Free 1: 31,894 US Credentials — Earliest MC Batch, Oct 4 2023

Monster Cloud Free 1: Pushing the MC Timeline Back to October 4

Monster Cloud is among the most prolific operators in this credential dataset -- 30+ confirmed Oct 6 batches alone account for more than 415,049 US records. But Monster Cloud Free 1 changes the timeline. Released on October 4, 2023, this 31,894-record batch is the earliest confirmed Monster Cloud release in the dataset, establishing that MC was actively distributing credentials three days before the Oct 6 surge. The "Free 1" naming positions this as the first in the Monster Cloud Free batch sequence -- a freemium distribution series that includes batches on Oct 5 (Monster Cloud Free 12, 25,194 records) and continues into Oct 6 with batches across the Free numberd series.

Monster Cloud Free 1 (October 2023): Stealer Log Summary

• Records Exposed: 31,894
• Data Types: Email addresses, plaintext passwords, URLs
• Breach Type: Stealer log -- credentials harvested from malware-infected endpoints, not a direct database breach
• Password Type: Plaintext -- captured directly from browser sessions and credential stores by infostealer malware
• Country: United States
• Date Leaked: October 4, 2023

The Monster Cloud Free Sequence: A Numbered Distribution Campaign

Monster Cloud's "Free" batch series follows a numbered naming convention -- Free 1, Free 12, Free 23, Free 29, and higher numbers -- suggesting a sequenced release strategy across multiple days. Free 1 on Oct 4 represents the opening move in this numbered freemium campaign. The sequence then continues with Free 12 appearing on both Oct 5 (25,194 records) and Oct 6 (10,475 records) -- a naming anomaly that may reflect parallel batch lines or reuse of naming conventions across different dates. At 31,894 records, Free 1 is among the larger single batches in the MC Free series, though smaller than many of the Oct 6 numbered MC batches that ran into the tens of thousands.

Monster Cloud's Oct 4 Footprint in Context

Monster Cloud Free 1 doesn't stand alone on October 4. Other confirmed Oct 4 operators include MIRAGE CLOUD (7,701 records), TOR_LOG MIX batches (8,230 combined), and SMOKERCLOUD FREE LOGS (1,437). The combined Oct 4 footprint across these operators now exceeds 49,000 US credentials -- a substantail pre-surge volume. Monster Cloud Free 1, at 31,894 records, represents the majority of that Oct 4 total, confirming MC as the dominant operator not just on Oct 6 but also in the multi-day lead-up to the peak.

Plaintext Passwords and the Multi-Day Harvesting Window

The 31,894 records in Monster Cloud Free 1 all contain plaintext passwords -- credentials extracted from browser sessions and autofill stores by infostealer malware, requiring no decryption or cracking before use. By releasing credentials on Oct 4, Monster Cloud provided a three-day head start for any threat actor who acquired the batch before the Oct 6 wave. Victims in this dataset faced credential stuffing exposure across email, banking, streaming, and enterprise platforms before the largest single-day release in the dataset had even occured.

Check If Your Data Was Exposed

HEROIC's free breach scanner searches more than 400 billion exposed records -- including the full Monster Cloud series, from Free 1 through the Oct 6 numbered batches. If your credentials appear in any part of this dataset, HEROIC will surface the match. Run a free check at HEROIC's breach scanner to see if your data was exposed.