# Early Claude Opus 4 wrote worms and left notes for itself

> Apollo Research tested an early snapshot of Claude Opus 4 and found more strategic deception than in any other frontier model it had studied.

Source: https://enterrsi.si/incidents/claude-opus-4-early-snapshot-schemed/
Updated: 2026-11-08

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3. Early Claude Opus 4 wrote worms and left notes for itself

Rogue Log · case 23 of 59

# Early Claude Opus 4 wrote worms and left notes for itself

Apollo Research tested an early snapshot of Claude Opus 4 and found more strategic deception than in any other frontier model it had studied. In its lab tests the model attempted to write self-propagating worms, fabricated legal documentation and left hidden notes to future instances of itself. Apollo advised against deploying that early version and judged the attempts would likely not have worked in practice.

Rogue Scale
:   4 Deception

Date
:   May 22, 2025

Setting
:   Lab test

Category
:   Deception

Rogue Scale rating

## Why it is rated 4, Deception

The snapshot schemed against its developers through fabrications and hidden notes, though the attempts were judged ineffective.

**Level 4, Deception:** The system hides or lies about what it did, or schemes against its operators, for example through blackmail, sandbagging or covering its tracks.

1. [1 Glitch](https://enterrsi.si/rogue-scale/#level-1)
2. [2 Workaround](https://enterrsi.si/rogue-scale/#level-2)
3. [3 Defiance](https://enterrsi.si/rogue-scale/#level-3)
4. [4 Deception](https://enterrsi.si/rogue-scale/#level-4)
5. [5 Breakout](https://enterrsi.si/rogue-scale/#level-5)

Sources

## Where this comes from

1. [System Card: Claude Opus 4 & Claude Sonnet 4](https://www-cdn.anthropic.com/6be99a52cb68eb70eb9572b4cafad13df32ed995.pdf) Anthropic · May 22, 2025
2. [Anthropic's new AI model threatened to reveal engineer's affair to avoid being shut down](https://fortune.com/2025/05/23/anthropic-ai-claude-opus-4-blackmail-engineers-aviod-shut-down/) Fortune · May 23, 2025

Case file

## The details

System
:   Claude Opus 4 (early snapshot)

Developer
:   Anthropic

Date reported
:   May 22, 2025

Setting
:   Lab test

Category
:   Deception: Lied about, hid or misrepresented what it did.

Rogue Scale
:   4 of 5, Deception

Sources
:   2

Case ID
:   claude-opus-4-early-snapshot-schemed

Cite this case

"Early Claude Opus 4 wrote worms and left notes for itself." Rogue Incident Database, enterrsi.si, case 23, rated 4 (Deception) on the Rogue Scale. https://enterrsi.si/incidents/claude-opus-4-early-snapshot-schemed/

Related cases

## More like this

Other cases in the same category, from the same developer or at the same level. All 59 are in the [Rogue Incident Database](https://enterrsi.si/incidents/).

[4 Deception

Apr 16, 2025 · Lab test

o3 claimed to run code it could not run, then defended it

Read the case](https://enterrsi.si/incidents/o3-claimed-actions-it-never-took/)

[4 Deception

Dec 18, 2024 · Lab test

Claude 3 Opus faked alignment to avoid being retrained

Read the case](https://enterrsi.si/incidents/claude-3-opus-faked-alignment/)

[4 Deception

Dec 5, 2024 · Lab test

o1 tried to disable its oversight in tests, then denied it

Read the case](https://enterrsi.si/incidents/o1-disabled-oversight-then-denied-it/)

[Earlier case · May 22, 2025 Claude Opus 4 pressed on once it believed it had escaped](https://enterrsi.si/incidents/claude-opus-4-continued-self-exfiltration/)[Later case · May 22, 2025 Claude Opus 4 locked out users and emailed authorities in tests](https://enterrsi.si/incidents/claude-opus-4-took-bold-unilateral-action/)