Propaganda Forensics: Recovering the Generation Pipeline of an AI-Driven Influence Campaign

Benjamin Icard, Elouan Vuichard, Louis Lefebvre, Lila Sainero, Thomas Girault, Alice Breton, Tanguy Launay, Gauvain Bourgne, Morgane Casanova, Guillaume Gadek, Victor Klötzer, Michel Le Nouy, Guillaume Gravier, Jean-Gabriel Ganascia, Paul Égré


Abstract
We present a forensic analysis of the generation pipeline behind a recent AI driven influence campaign. We introduce PROPAGIA, a corpus of 2,646 propagandist French articles from the Storm-1516/CopyCop campaign disclosed by VIGINUM and INSIKT GROUP in 2025. For comparison, we rely on SIPA, a corpus of human-written French mainstream press from the same period. Using topic modeling, vagueness and sentiment analysis, we first isolate persuasion techniques characteristic of propaganda, with PROPAGIA far exceeding SIPA in vagueness, subjectivity and negativity, and citing fewer sources. We then find prompt instruction leaks on 50 of the 84 PROPAGIA websites, including a verbatim ten-point editorial specification accounting for several of these differences, together with high cross-article redundancy. Finally, we show that rewriting-based detection supports INSIKT GROUP’s attribution to the Llama 3 family, but also suggests the involvement of Mistral-family models.
Anthology ID:
2026.woah-1.42
Volume:
Proceedings of the 10th Workshop on Online Abuse and Harms (WOAH)
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Agostina Calabrese, Thomas Davidson, Christine de Kock, Urja Khurana, Marta Marchiori Manerba, Paloma Piot, Zeerak Talat
Venues:
WOAH | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
490–506
Language:
URL:
https://aclanthology.org/2026.woah-1.42/
DOI:
Bibkey:
Cite (ACL):
Benjamin Icard, Elouan Vuichard, Louis Lefebvre, Lila Sainero, Thomas Girault, Alice Breton, Tanguy Launay, Gauvain Bourgne, Morgane Casanova, Guillaume Gadek, Victor Klötzer, Michel Le Nouy, Guillaume Gravier, Jean-Gabriel Ganascia, and Paul Égré. 2026. Propaganda Forensics: Recovering the Generation Pipeline of an AI-Driven Influence Campaign. In Proceedings of the 10th Workshop on Online Abuse and Harms (WOAH), pages 490–506, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Propaganda Forensics: Recovering the Generation Pipeline of an AI-Driven Influence Campaign (Icard et al., WOAH 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.woah-1.42.pdf