JQ parsing of escaped quotes

We have an AWS autoscaling lifecycle hook that is placing messages on an SQS queue. We are trying to parse these with JQ, and while the format is mostly JSON, all the key/value pairs within the body object have escaped double quotes. Can't seem to find an AWS option to not escape the quotes, or a JQ option to successfully parse them. Example here:

    {
    "Messages": [
        {
            "Body": "{
\"Origin\":\"AutoScalingGroup\",
\"LifecycleHookName\":\"termination_lifecycle_hook\",
\"Destination\":\"EC2\",
\"AccountId\":\"<redacted>\",
\"RequestId\":\"65e1eaeb-1bde-42ef-93b5-ac14987a2848\",
\"LifecycleTransition\":\"autoscaling:EC2_INSTANCE_TERMINATING\",
\"AutoScalingGroupName\":\"test-um-prod-20230822043811258400000005\",
\"Service\":\"AWS Auto Scaling\",
\"Time\":\"2023-08-29T20:42:36.581Z\",
\"EC2InstanceId\":\"i-02ca28b1a415a4d48\",
\"LifecycleActionToken\":\"1e7f23b9-4a9a-4cad-9051-6039d815e9b1\"
}",
            "ReceiptHandle": "AQEBN8E7SCNS44lemWqlfMVvOl9EfGo7Yb5b+VhF5jXlw2i41pwQJFvfaAFwBEquO8SOsGyaIUfFiE9qEUQoQOgyUoz5a+Rx/yD9jq2qfz/gRcSwhfCAPHyBvhjJdIGmlyKtNnTzuL183Wti4BO4G+Z7bLzn/WiIT+JrSfn/VofI34HnB0w0Om3UYTnd6OoXuCu2WxzasyMeFcImuCYdt+5+tMzauEtsL7EVdSZwpW3S4oatkuxfzzyxHsP4X0IIKt6fwIzHzCRhi9kmo5QnZAQCnjHo+RBNZXWU9wbk3SToE3nCdLJhbups5SOHAUHLO1PwdVb7RvKMmYYdHfzoTQBLeWJ1w7MEMrhANC9uOu7cVzS0hAAc9qPLzzoV1TkIBn/0Q597cl6dNyfkWpPQEOKtUg==", 
            "MD5OfBody": "fa2bc63f28d96c532288b09831a8b73f", 
            "MessageId": "4c5b0c2c-9085-4bde-8de3-49ae3f63afd4"
        }
    ]
}

As you can see, all objects except "Body" are fine, but all the key/values within "Body" are escaped.

Solution

You can use the fromjson function for parsing JSON-encoded values. In your case, that would be

jq '.Messages | .[] | .Body | fromjson'