The era of global malware, characterized by threats like Blaster and MyDoom, is drawing to a close. Malware authors have taken to designing malicious code for local markets.

A report that McAfee plans to release on Thursday describes how malware creation over the past few years has transformed from a mass market endeavor into a regional one.

"We could not have had this conversation two or three years ago," said Dave Marcus, security research and communications manager for McAfee Avert Labs. "People are writing malware that targets the specific behaviors of local people."

One reason for this is that different applications are popular in different countries.

The Japanese, for instance, are heavy users of a peer-to-peer file sharing program called Winny. Its success has lead to Winny-specific malware.

The Chinese, meanwhile, participate heavily in online gaming: A quarter of all Chinese Internet users play online games, according to McAfee. As a consequence, Chinese gamers face a plague of password stealing programs distributed by cybercrminals looking to loot valuable virtual goods from gamers' accounts.

"China sees lots of gaming security issues," said Marcus.

And in Brazil, where online banking is popular, the password stealing programs tend to target real banks. Another reason that malware has become more localized is that social engineering attacks work best when they take local customs and practices into account.

A proof-read, idiomatically correct phishing letter in the recipient's local language is far more likely to dupe its recipient than a scam in some unintelligible tongue. "You've got a dedicated group of producers that are really going out of their way to find people with local language skills," explained Marcus.

The evolution of malicious messages in Germany represents an example of this trend. "In the early days, messages were composed in crude German notation that looked like it was an English or Russian text translated by Babel Fish," the McAfee report says. "Today, we read text written in perfect German, referring to current events and playing on people's hopes."

The Zunker trojan demonstrates the emerging geo-awareness of malware. It's a password stealer that also sends spam and malicious Web links. It inserts these links in e-mail sent by the victim, who is unaware his or her computer has been compromised, and generates a localized phrase to support the link in a language appropriate for the recipient. The goal is to make the recipient more likely to click on the malicious link.

Localization also helps when dealing with country-specific infrastructure. The Spy-Agent.ba trojan, for example, is designed to hijack home banking connections and steal user credentials. According to the McAfee report, its functions are optimized for different corporate targets in Germany.

If there's an upside to all this, it may be that much of the 246% growth in malware McAfee saw from 2006 through 2007 consists of malicious programs designed for someone or someplace else. Then again, like "security through obscurity," "security through geography" isn't really a winning long-term strategy.