Vulnerabilities / Threats
10/19/2009
05:31 PM
Connect Directly
Google+
Twitter
RSS
E-Mail
50%
50%

Botnet Unleashes Variety Of New Phishing Attacks

Attackers use phony messages of system upgrades, Outlook updates, and Microsoft Conficker 'cleanup tool' to spread malware

The massive Zbot botnet that spreads the treacherous Zeus banking Trojan has been launching a wave of relatively convincing phishing attacks during the past few days -- the most recent of which is a phony warning of a mass Conficker infection from Microsoft that comes with a free "cleanup tool."

The wave of attacks began early last week targeting corporations in the form of email messages that alerted victims of a "system upgrade." Email is accompanied by poisoned attachments and links; in some cases it poses as a message from victims' IT departments, including their actual email domains, and alerts them about a "security upgrade" to their email accounts. The message then refers victims to a link to reset their mailbox accounts, and the link takes them to a site that looks a lot like an Outlook Web Access (OWA) page (PDF), but instead infects them with the Zeus Trojan.

Today, researchers at F-Secure spotted the botnet spamming out malware-laden email that tries to trick recipients with a convincing lure messages that says, "On October 22, 2009 server upgrade will take place."

"What we're seeing is an evolving campaign of different lures to see which one works," says Richard Wang, manager of Sophos Labs in the U.S.

The Zbot botnet, which is made up of 3.6 million PCs in the U.S., or 1 percent of all PCs in the country, according to data from Damballa, spreads the deadly Zeus Trojan. Zeus, which steals users' online financial credentials, represents 44 percent of all financial malware infections today, according to Trusteer.

But according to Trend Micro's Paul Ferguson, the Zbot botnet isn't actually behind the latest attacks: it's the fast-flux Avalanche botnet, which is hosting Zeus and Zbot Trojans.

The Shadowserver Foundation has seen multiple versions of Zeus-related attacks lately, including the Conficker "cleanup utility" that poses as an email from Microsoft, according to Andre DiMino, director of Shadowserver. And the targeted Outlook attacks use real domains: "What is also interesting about the recent campaign is that the email comes from the targeted user's own domain with an 'administrator' prefix. The link is disguised to look like it's from an update server on the local domain, but instead points to the malicious location," DiMino says.

Amit Klein, CTO at Trusteer, says the Conficker phishing email was pushing fake antivirus software and, in some cases, also contains Zeus, so he's not convinced that attack is necessarily coming from the same gang behind the Outlook and other phishing campaigns. "I really don't know" if it's the same Zbot botnet behind those two attacks, he says. "But if it's spreading the same malware with a similar concept [of a phishing attack], it does raise suspicion that the two events were by the same gang, or it could be a copycat."

The Outlook attack was the first large-scale Zeus attack against the corporate world, he says, which signals a new strategy for Zbot. "Shifting its focus there makes a lot of sense for financial malware because the typical credentials you can steal from the corporate world are worth a lot more money than credit cards and accounts in the consumer world. To own the company's accountant or finance department's bank account credentials would be a lot more profitable," Klein says.

Zeus traditionally has been one of the more difficult malware variants for some antivirus programs to detect: According to recent data from Trusteer, Zeus is detected only 23 percent of the time by up-to-date antivirus applications. It's also hard to kill because it hides itself so well in the operating system.

Trusteer's Klein says this new wave of phishing attacks from Zbot is just the beginning. "These are new flavors, and we're going to see a lot more of these in the future," he says. "This has proved to be highly effective."

Have a comment on this story? Please click "Discuss" below. If you'd like to contact Dark Reading's editors directly, send us a message. Kelly Jackson Higgins is Executive Editor at DarkReading.com. She is an award-winning veteran technology and business journalist with more than two decades of experience in reporting and editing for various publications, including Network Computing, Secure Enterprise ... View Full Bio

Comment  | 
Print  | 
More Insights
Register for Dark Reading Newsletters
White Papers
Cartoon
Latest Comment: nice post
Current Issue
Flash Poll
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2014-1750
Published: 2015-07-01
Open redirect vulnerability in nokia-mapsplaces.php in the Nokia Maps & Places plugin 1.6.6 for WordPress allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via a URL in the href parameter to page/place.html. NOTE: this was originally reported as cross-sit...

CVE-2014-1836
Published: 2015-07-01
Absolute path traversal vulnerability in htdocs/libraries/image-editor/image-edit.php in ImpressCMS before 1.3.6 allows remote attackers to delete arbitrary files via a full pathname in the image_path parameter in a cancel action.

CVE-2015-0848
Published: 2015-07-01
Heap-based buffer overflow in libwmf 0.2.8.4 allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via a crafted BMP image.

CVE-2015-1330
Published: 2015-07-01
unattended-upgrades before 0.86.1 does not properly authenticate packages when the (1) force-confold or (2) force-confnew dpkg options are enabled in the DPkg::Options::* apt configuration, which allows remote man-in-the-middle attackers to upload and execute arbitrary packages via unspecified vecto...

CVE-2015-1950
Published: 2015-07-01
IBM PowerVC Standard Edition 1.2.2.1 through 1.2.2.2 does not require authentication for access to the Python interpreter with nova credentials, which allows KVM guest OS users to discover certain PowerVC credentials and bypass intended access restrictions via unspecified Python code.

Dark Reading Radio
Archived Dark Reading Radio
Marc Spitler, co-author of the Verizon DBIR will share some of the lesser-known but most intriguing tidbits from the massive report