# Pravda, RT poison Common Crawl LLM training data

Published: 2026-04-08 · Severity: routine · Sectors: technology, government-national, media
Canonical: https://vorant.io/reports/dc783907-c2ed-549c-b712-94bb6a8ec88e/pravda-rt-poison-common-crawl-llm-training-data

> Russian state propaganda embedded in Common Crawl archive is being ingested by large language models, poisoning their outputs on geopolitical topics.

The DFRLab has documented systematic insertion of Russian state propaganda—including content from the Pravda network and RT—into Common Crawl, the public web archive that supplies training data for most open-weights large language models. An audit found approximately 40,000 English-language Pravda articles archived as of November 2025, up from 37 in November 2024. Testing with Llama 3.1 405B Base confirmed that models can reproduce RT's biolab disinformation nearly verbatim, demonstrating that the poisoning has already affected deployed systems. The mechanism is deliberate: Pravda configures its robots.txt and sitemaps to maximize crawling and indexing by Common Crawl's bot, ensuring rapid archival of propaganda content. Once baked into model weights during training, this content cannot be easily removed without expensive full retraining. The DFRLab also identified Chinese state-adjacent content from Glassbridge in Common Crawl, though JavaScript-based page architecture limited its ingestion into tested models. The threat is asymmetric: only 250 malicious documents can compromise even very large models, but defenders cannot surgically remove poisoned training data post-deployment. The risk intensifies as open-weights model development lags behind frontier systems and encounters Pravda material in the wild.

## Mentioned in this report

- Threat actors: Glassbridge, Pravda Network
- Campaigns: Doppelgänger

1 detection for this report is in the app: the rules that match its indicators, the Sigma rules already converted to Splunk SPL, to Elastic where their fields map onto Elastic's integrations and to Microsoft Defender XDR KQL wherever Defender records the activity, and the YARA and Suricata. A new account gets three days of them free.

Source reporting: https://dfrlab.org/2026/04/08/pravda-in-the-pipeline

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