NTT DoCoMo, Japan's top wireless carrier, is warning customers of its iMode wireless Internet service about malicious e-mail messages that can use special commands to freeze the screens of their mobile phones, dial an emergency number automatically or make calls to large numbers of people.
The Tokyo-based company issued a statement Wednesday advising customers of the problem.
The company said that although users hadn't reported any damage resulting from the malicious e-mail, it was considering legal action against the senders because of the inconvenience to customers. A company spokesperson couldn't be reached for comment at deadline.
NTT DoCoMo said iMode customers should take these steps: They shouldn't open e-mails from senders they don't know; they should press the Stop or Power button if the phone starts to dial a third party automatically; if the mobile phone starts to send e-mails to a third party automatically, the user should push the Clear button; if the mobile phone's screen freezes, the user should remove the battery, reinsert it and then restart the handset.
NTT DoCoMo, which plans to launch the iMode service in the US next year in conjunction with AT&T Wireless Group, said handsets that will be sold beginning in July won't be affected by the commands embedded in the malicious e-mails.