YOULOGS 376logsMix: 11,012 Stolen US Credentials — Highest Yield in Oct 3 Dataset

YOULOGS 376logsMix: Unpacking the Dataset with the Highest Per-File Yield on October 3

When comparing the per-file yield across confirmed October 3, 2023, stealer log batches, YOULOGS 376logsMix stands apart. At ~29.3 records per source file -- nearly 2.5 times the average for that day's operators -- this batch suggests either exceptionally well-targeted endpoint infections or an agregated dataset combining credentials from multiple collection sources. The "MIX" suffix is a common indicator of aggregation, and the "376logs" count represents individual source files. With 11,012 total records spread across 376 files, this yeild figure is the highest confirmed in the dataset and warrants a closer look at what it implies.

YOULOGS 376logsMix (October 2023): Stealer Log Summary

• Records Exposed: 11,012
• 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: USA
• Date Leaked: October 3, 2023

Why Per-File Yield Matters: Endpoint Quality and Targeting

In the stealer log market, per-file yield is a proxy for the quality of the infected endpoints. Standard consumer device infections -- where a home user has saved a handful of passwords -- typically produce 8-12 records per file. Mid-range endpoints (small business users, professionals) may yield 15-20 records. YOULOGS' 29.3 records per file falls well above this range, pointing to one of two scenarios: the malware campaign specifically targeted high-value endpoints with many saved credentials (corporate machines, power users), or the "MIX" designation reflects aggregation of multiple source lists into each logical file, artificially inflating the per-file count. Either scenario is significant -- the first implies sophisticated targeting, the second implies active data curation by the operator.

YOULOGS as a Multi-Day Operator

YOULOGS 376logsMix is not the only confirmed batch from this operator. A second batch -- YOULOGS 260pcsMIX -- was released on October 2, 2023, the day before this release, containing 5,061 records across 260 source files (~19.5 records/file). The combined YOULOGS total across both dates is 16,073 records. The yield jump between the Oct 2 batch (19.5) and the Oct 3 batch (29.3) is notable -- simillarly to patterns seen with other multi-day operators, the later batch may represent a curated subset of higher-quality endpoints rather than a continuation of the same infection campaign.

Mixed-Source Aggregation and Its Implications for Victims

The "MIX" label signals that credentials in this batch were harvested from multiple different endpoint infections or source campaigns rather than a single targeted operation. For affected individuals, this means the exposure may have originated from any number of different malware variants, infection vectors, or time periods -- not necessarily a single infection event. The plaintext nature of the passwords means each credential was immediately usable for credential stuffing, regardless of when the underlying infection occurred or which malware family captured it.

Check If Your Data Was Exposed

HEROIC's free breach scanner searches across more than 400 billion exposed records, including mixed-source stealer log collections like YOULOGS 376logsMix. With its exceptionally high per-file yield, this batch may contain credentials from a wide variety of compromised accounts and services. Run a free scan at HEROIC's breach scanner to find out if your data is in this or any other exposed dataset.