The malicious code could sign owners up to subscription services without permission.
New apps use your phone to record your dimensions and recommend what size to buy at shops.
Shahrzad Rafati is the boss of internet video technology firm BroadbandTV.
The website for tests in England and Wales crashes on the morning of relaunching following the lockdown.
The comments from the online retail giant's boss come as the firm saw sales jump in the wake of the pandemic.