The new security breach follows a massive theft of personal data from Sony's PlayStation Network and Sony Online Entertainment services, including names, passwords and addresses from more than 100 million accounts.
And on Tuesday Sony said its websites in three countries had been hacked with 8,500 Greek user accounts compromised, while sites in Thailand and Indonesia were also affected.
The most recent attack -- targeting the mobile phone joint venture between Sony and Sweden's Ericsson -- was discovered on Tuesday local time, and the affected website was shut down, a Sony spokesman told AFP.
"Sony Ericsson's website in Canada, which advertises its products, has been hacked, affecting 2,000 people," he told AFP.
"Their personal information was posted on a website called 'The Hacker News'. The information includes registered names, email addresses and encrypted passwords. But it does not include credit card information."
The link to the Sony Ericsson eShop site featured a message that said "D'oh! The page you are looking for has gone walkabout. Sorry."
The series of breaches has damaged Sony's brand image and undermined its efforts to link its gadgets to an online "cloud-based" network of games, movies and music that relies on consumer confidence in their security.
The Japanese entertainment and technology giant said data taken from Greek accounts included email addresses, telephone numbers, names and passwords but that credit card data had not been stolen in the latest attacks.
Sony said it also discovered on Saturday that a page on its Indonesian Music Entertainment website had been "altered" but did not believe this involved the leak of information.
On Monday Sony said it expected to post a $3.2 billion dollar net loss for the fiscal year ended March as it tries to recover from the impact of the March 11 earthquake and tsunami, which ravaged production and damaged facilities.
It said the data breach will result in at least a $170 million hit in "currently known costs" to operating profit this financial year in terms of insurance and damages, but that it anticipated further costs.
Sony has said it plans to fully restore PlayStation Network and Qriocity services by the end of the month.
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