Hawai'i's Better Business Bureau is warning local residents about malicious Web sites and Twitter posts trying to exploit recent natural disasters in Pacific island nations.

Unscrupulous Web site operators, under the guise of providing information about the earthquake and subsequent tsunamis that hit Samoa and Tonga, are attempting to trick consumers who click on their sites to download and purchase fake anti-virus software, the BBB said.

So-called "scareware" sales tactics designed to scare a user into thinking his or her computer contains critical errors or viruses that must be fixed immediately. For a price, scareware ads offer an instant solution in the form of downloadable software. In many cases the software meant to fix nonexistent errors is actually spyware or some form of malware itself, victimizing consumers twice.

Within hours of the natural disasters, scareware offers began hitting the Internet, the BBB said yesterday in a news release.

Scammers are quick to respond to newsworthy events, such as these natural disasters, because they know the topics create a lot of interest and concern, said Dwight Kealoha, chief executive officer of Hawai'i's BBB.

"There are two things you can count on after a major natural disaster," Kealoha said. "The first is the generosity of people looking for ways to help, and the second is the appearance of scammers looking to take advantage of their good will.

"Since Hawai'i has large Samoan and Tongan populations, many of whom have loved ones in these Pacific islands, we think it's important to warn about these malicious online activities," he said. "It's not unlikely that similar tricks are being used against people looking for information on the floods in the Philippines and now, the Indonesian earthquake, too."

Rogue anti-virus scammers use search engine optimization techniques to ensure that their Web sites are among Google's top results, Kealoha said. Scammers also use keywords based on Twitter's trending topics in related tweets.

To help protect against these malicious online scams, Hawai'i's BBB recommends computer users keep their anti-virus software current and ensure that all security patches and updates are installed for Web browsers and other Internet-based programs.

For more advice about online safety or finding trustworthy charities to support Pacific island disaster relief efforts, visit the BBB Web site at www.bbb.org.