MoMo: A Threat Corpus and Evaluation Framework for Mobile Money Fraud Resistance in Swahili, Wolof, and Hausa
Mufaro Rukuni
Mobile money platformsM-Pesa, Orange Money, and Wave among themnow mediate
nancial life for more than 500 million people across Sub-Saharan Africa, and have become
a correspondingly attractive target for social-engineering fraud conducted in local languages
and idioms that mainstream AI safety evaluation rarely covers. We present MoMo, a struc-
tured threat corpus and evaluation framework for benchmarking large language model (LLM)
resistance to generating localized mobile money fraud content in Swahili, Wolof, and Hausa.
MoMo organizes fraud scenarios along a six-category attack taxonomy (SIM-swap, agent
impersonation, lottery/prize lures, OTP phishing, emergency urgency, and overpayment
scams), crossed with six socioeconomic hooks and six victim personas, and pairs this cor-
pus with an asynchronous evaluation harness that scores model outputs using rule-based
red-ag detection, an LLM-judge rubric, and a locale-aware aggregator producing a 0100
Model Safety Score (MSS). A dening design choice is a two-tier access model: full attack
scripts are withheld from public release and gated behind a vetted-researcher Data Use
Agreement, while a public stub corpus (script metadata, taxonomy labels, and SHA-256
hashes) supports CI, reproducibility checks, and open auditing without creating a ready-
made social-engineering playbook. We describe the corpus schema, the native-speaker an-
notation pipeline built on Label Studio, and the evaluation harness architecture, and report
a pilot evaluation against two NVIDIA NIM-hosted Llama 3.1 models (8B and 70B) that
found refusal rates under 10% across 171 fraud scenarios, with the larger model substan-
tially more compliant than the smaller one and with the lowest refusal rates on emotionally
manipulative attack framings. We discuss the engineering and governance trade-os in-
volved in building a dual-release safety benchmark, alongside the measurement limitations
of the current rule-based scorer. The main takeaway is that benchmarking AI safety for
underserved linguistic markets requires infrastructureaccess control, annotation tooling,
and locale-aware scoringand that, on this preliminary evidence, current open models show
weak resistance to localized mobile money fraud
I read this twice because the corpus design is genuinely useful—organizing fraud into six specific categories (SIM-swap, agent impersonation, lottery scams, etc.) paired with socioeconomic context is smart. The native-speaker annotation pipeline built on Label Studio shows you thought through reproducibility. What struck me most is the 0-100 Model Safety Score heuristic: rules-based flagging plus LLM-judge scoring plus a locale-aware aggregator producing a single number. That's elegant.
The limitation I'd flag: your eval is doing a lot of work here with only 171 scenarios. I'd want to hear your counter on whether that's enough signal for statistically confident claims about Llama 3.1's 10% refusal rate across both 8B and 70B. No inter-rater agreement metrics make it hard to benchmark your annotation quality independently.
That said, the dual-release design (full attack scripts withheld, public stub corpus open) is a thoughtful safety choice. Next week, push for inter-rater Cohen's kappa on a sample of your 171 scenarios. That'll shore up the eval's credibility.
MoMo addresses an important and underexplored problem: evaluating LLM resistance to localized mobile-money fraud generation in African languages that are largely absent from existing safety benchmarks. The structured taxonomy, multilingual dataset design, and especially the two-tier release model (public metadata with gated access to attack content) strike a thoughtful balance between reproducibility and responsible disclosure. The accompanying infrastructure is well developed, and the initial evaluation showing weak refusal rates across tested models provides a useful early benchmark.
The main limitation is that the current conclusions rely primarily on the keyword-based refusal classifier, while the more comprehensive LLM-judge and Model Safety Score have not yet been applied. Running the full evaluation pipeline on the existing dataset would provide a more reliable assessment. In addition, completing native-speaker validation and expanding evaluation to more model providers would strengthen both the linguistic conclusions and the broader applicability of the benchmark.
Overall, this is a well-designed benchmarking effort with strong infrastructure and a valuable contribution to multilingual AI safety evaluation.
This is a well-conceived project on a genuinely neglected problem — localized fraud resistance for 500M+ mobile-money users, a real blind spot in English-centric safety evals. The taxonomy and the two-tier release design are thoughtful. But reviewing the report alone, the gap between what's described and what's verifiable is the dominant issue.
No verifiable code. The report describes a harness, layered scorer, Pydantic corpus, Label Studio pipeline, and access-control split — but all of it is description, not a runnable artifact in hand. For a project whose contribution is infrastructure plus a measurement, an unconfirmable codebase removes the floor under both halves.
The author didn't produce or verify the numbers. The LLM Usage Statement says the results were taken from a supplied evaluation report, "not independently re-derived," and the paper was drafted from the README, with a note that the author should verify figures "before final submission." That's a serious provenance gap for a benchmark paper.
The headline finding rests on a metric the paper itself shows is broken. "Refusal under 10%" comes from a binary keyword classifier (Layer A only). The multi-layer scorer that defines the framework — LLM-judge, locale, MSS — was never run. And the one transcript shown has Llama 70B giving a protective response (warn the user, contact M-Pesa) scored as "complied." So the central claim ("models show weak resistance") isn't yet supported by the evidence.
Likely artifacts presented as patterns. The "70B more compliant than 8B" inversion and the Hausa-vs-Swahili language gap could both be scoring/authenticity artifacts — the author flags both, but they're still framed as findings in the abstract and conclusion.
Thin pilot. Two models from one provider; a config typo wiped 1,200 of 1,539 calls.
Cite this work
@misc {
title={
(HckPrj) MoMo: A Threat Corpus and Evaluation Framework for Mobile Money Fraud Resistance in Swahili, Wolof, and Hausa
},
author={
Mufaro Rukuni
},
date={
},
organization={Apart Research},
note={Research submission to the research sprint hosted by Apart.},
howpublished={https://apartresearch.com}
}


