Security news23 September 2004
Ireland bans calls to 13 countries to tackle premium rate telephone fraud, Sophos comments
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| Some rogue dialers call phone numbers based on islands in the Pacific, leading to expensive bills. |
Phone a friend? Not in the Cook Islands, Mauritania, French Polynesia...
ComReg, Ireland's telecoms regulator, has taken the radical step of blocking calls to 13 different countries, including the Cook Islands and Mauritania, in a bid to combat the growing problem of internet users being stung by extortionate phone bills.
Thousands of dial-up internet users have been affected by Trojan horses which have silently embedded themselves in PCs and taken over modem connections to make calls to expensive premium rate overseas numbers, instead of the usual freephone ISP codes. Known as "rogue dialers", the Trojans allow fraudsters to earn a small fortune.
"These rogue dialer Trojan horses make secret phone calls to expensive premium rate numbers without your knowledge. By the time you receive a massive, completely unexpected telephone bill at the end of the month it's too late," said Graham Cluley, senior technology consultant for Sophos. "Ireland has taken a bold step to protect consumers by suspending calls to certain countries, it will be interesting to see if other European operators will follow suit to protect their users."
Irish telephone users who wish to telephone the thirteen countries, most of which are tiny islands in the Pacific Ocean, will be able to request that specific numbers are unblocked.
In June, the UK's telephone regulator ICSTIS reported a significant rise in complaints about rogue dialers, forcing it to ask the National Hi-Tech Crime Unit (NHTCU) to investigate.
Sophos advises users that dialers are not likely to affect broadband users, but only computer users who still connect to the internet via a dial-up modem.
Anti-virus software like Sophos Anti-Virus can detect known Trojan horses that secretly change dial-up settings, but as there are more being written all the time computer users are advised to be very careful about software they allow to run on their computer. Broadband users are recommended to check whether their computer still has a dial-up modem connected to a telephone line, which could be exploited by this type of attack.
"Computer users need to protect their PCs from all the nasties spreading on the internet. Trojans are just one threat that can prove extremely costly, but can be tackled by making sure that anti-virus software is kept up-to-date," continued Cluley.
The countries on the Irish "banned list", which comes into force on 4 October 2004, are those said to have been named in the majority of complaints: Norfolk Island, Nauru, Sao Tome and Principe, Cook Islands, Tokelau, Diego Garcia, Wallis and Fortuna, Tuvalu, Comoros, Kiribati, Solomon Islands, Mauritania and French Polynesia.
