Up to 1000 Salesforce.com customers in Australia fear their corporate data is in the hands of hackers after the company was targetted by a phishing scam and one of the vendor's employees was tricked into divulging a corporate password this week.

Desperate to obtain details about the attack Australian customers have been forced to contact Salesforce.com in the United States as the vendor has not notified a single user locally that was contacted by Computerworld.

Users contacted by Computerworld were alarmed by news of the attack confirming that they had not been warned by Salesforce.com although they eagerly awaited a briefing so steps could be taken to protect their organizations.

There was some information made available in the United States with customers sent a note advising online criminals have been sending customers fake invoices and, starting just a few days ago, viruses and key logging software. The e-mails were sent using information that was illegally obtained from Salesforce.com.

Salesforce.com bills its Web-based CRM (customer relationship management) products as easier to use and maintain than traditional CRM software, but this latest development underlines the security risks that come with this more open model.

The problems began a few months ago, when a Salesforce.com employee fell for a phishing scam and divulged a company password that gave attackers access to a customer contact list. With this password, the criminals were able to obtain first and last names, company names, e-mail addresses and telephone numbers of Salesforce.com customers.

Some of those customers then fell victim to the scam and gave up their passwords to the criminals, too. When Salesforce.com started seeing malicious software being attached to these e-mails, the company decided to issue a general alert to its nearly one million subscribers.

Australian customers account for 1000 of the vendor's 35,300 subscription base worldwide. But every company contacted by Computerworld about the attack were completely in the dark not knowing that customer contact lists had been exposed.

A spokesperson at networking and communications provider, Adtran, said it was forced to contact the United States in a bid to get details on how the scam impacts customers.

One customer, Honda Motorcyles and Power Equipment, is currently rolling out Salesforce.com and was shocked by news of the incident.

Other customers including Honda and AAPT were also unaware of the client database breach which allowed a hacker to launch a spate of personalised phishing attacks to build a global botnet.

The Ukraine-based attacker then infected up to 500 PCs with a Trojan Horse and keylogger, sent as attachments to customised phishing e-mails which included customer first and last names, e-mail addresses, company titles, telephone numbers and employer details.

Salesforce.com customers who opened the links or executable file in the apparent Salesforce.com invoice were infected with a kbd.dll trojan horse (PSW.generic5.tlw) and keylogger.

The malware then captures and uploads real time screenshots and keystrokes to publicly available and unauthenticated Web servers.