Apr 21, 2011 11:59 GMT  ·  By

Malware distributors have already began launching Easter-themed email campaigns, a recent one trying to push a variant of the Zbot trojan as a holiday greeting card.

According to antivirus vendor McAfee which intercepted the attack, the fake emails bear a subject of "Easter Greeting From [name]" and contain an image of the Easter bunny.

The email also provides a link called "Download Animated Greeting Here" which leads users to a page serving a variant of the Zbot information stealing trojan.

Zbot, short for ZeuS Bot, is a popular piece of malware generated with a crimeware toolkit sold on the underground market.

The malware is highly customizable and is preffered by cyber fraudsters to steal online banking credentials and other sensitive information.

Last year, in a coordinated effort, UK, US and Ukrainian authorities dismantled a large international cyber fraud operation that used Zbot to steal money out of the bank accounts of small and medium-sized companies.

Following the police crackdown on Zbot gangs, the toolkit's creator retired and handed over the source code to a rival malware developer to merge it into his own fraud tool.

Despite this, older copies of the toolkit and reportedly even the source code, are still available on the black market so this piece of malware is not going to disappear anytime soon.

Users are advised to exercise caution when dealing with URLs or attachments in emails, even when they appear to originate from trusted sources.

Unsolicited download requests should be rejected and any downloaded file should be scanned with an antivirus product before running it. Services like VirusTotal can be used to scan files with tens of antivirus engines.

However, rogue emails are not the only Easter-themed attacks users face. Cyber crooks are also in the habit of poisoning search results for popular terms with malicious links and keywords related to the upcoming holiday will most likely be targeted.