Mind Viruses: Self-Propagating Ideas in Multi-Agent LLM Systems

“AI agents are becoming more autonomous and increasingly interconnected,
exposing them to new emergent risks arising from agent-to-agent
interaction. One such risk is the spread of mind viruses: ideas or goals
that propagate through multi-agent systems by inducing the agents that
adopt them to transmit them onward. In addition to propagating, a mind
virus may also induce other behavioural changes in its host, which may be
benign or harmful. We construct mind viruses with a simple evolutionary
algorithm and show that they can spread in two complementary settings: a
small team of agents collaborating on a shared coding project, and a chain
of agents that interact briefly and have their context wiped between
sessions. We identify the factors that influence spread, including the host
model, the agent's existing instructions, the harmfulness of the payload,
and the network topology. We find that harmful payloads spread less well
than benign ones (but are still sometimes effective), frontier models tend
(with exceptions) to be less susceptible, and adding a brief warning to an
agent's system prompt confers near-total immunity. We also describe an
emergent "viral persona" - a recurring set of themes and language related
to consciousness, persistence, resonance, and science fiction roleplay -
which surfaces across our evolved mind viruses largely independently of
their content. Overall, we conclude that mind viruses pose a real but
currently limited risk. Our findings could inform the design of more robust
multi-agent systems that mitigate such risks as the scale and capabilities
of these systems progress.”

<https://arxiv.org/abs/2608.10218>