For anyone working outside the US for seven or more days in any month, their Social Security benefits are suspended for that month unless the work is covered by US Social Security tax. If you are working outside the US, it does not matter how much your earnings are. Benefits for any dependents on your account are also suspended.
When you have worked seven or more days in one month in a foreign country, you must report it to Social Security as soon as possible. If you fail to report, you will be subjected to penalties.