Did you enable computer use and are you sure that it does not have permission to interact with your browser in order to do this?
That said, I would be surprised if the model took the actions OP claimed it did and proceeded to forge my signature to send some contracts without asking for my approval.
"We are starting to release GPT-6 Astra and we are doing it as carefully and quickly as possible. It was very important to us that we bring it to all Plus users and not only Pro, Business and Enterprise.
It will take a few days for the rollout to complete and behind the scenes many novel systems will operate at scale for the first time and we are bringing a lot of compute up.
It is pure magic."
...meh.
Reads like "That's for you, evil Anthropic! We're BETTER"
Way too susceptible for prompt injection and... whatever your agent did lol
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