Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Risk

Drive-By Downloads: Malware's Most Popular Distribution Method

After years of burying malicious software in email and portable storage media, attackers now favor quick downloads via legitimate websites, researcher says

WASHINGTON, D.C. -- OWASP AppSec DC 2010 -- Why try to fool users into opening email attachments when you can simply drop a Trojan on them from their favorite websites?

That's the question many malware authors and distributors are asking -- and the obvious answer is spurring most of them to try out the emerging "drive-by download" method, according to a speaker here this week.

"What we're seeing is a fundamental change in the method of malware distribution," said Neil Daswani, CTO of Dasient, which offers a service that detects and eradicates Web-borne malware. "In the old days, we saw executable code in a static file, which was originally delivered via floppy disks and then via email attachments. Now we're seeing active content delivered via drive-by downloads at legitimate sites."

A drive-by download typically begins by injecting a Web page with malicious code, often through JavaScript, Daswani explained. The code generally invokes a client-side vulnerability to deliver shell code, such as the JavaScript-based Heap Spray attack, to take control of the user's machine. From there, the attacker can send a "downloader," which is often custom, zero-day code that isn't recognized by traditional antivirus systems.

Once the downloader is in place, the attacker can deliver his malware of choice, Daswani said. Drive-by downloads are particularly effective for delivering code that can steal end user credentials (such as Zeus), launch a fake antivirus scam (such as Koobface), steal server-side administrative credentials (such as Gumblar), steal corporate secrets (such as Project Aurora), or collect fraudulent click revenue (such as clickbot.A), he noted.

While drive-by downloads are often more effective at infecting end user devices than email attachments, they also give the attacker broader reach, Daswani observed. Drive-by downloads can be used to infect thousands of websites at once, often by hiding in common third-party devices that are distributed to many sites, such as advertisements, widgets, images, or third-party applications.

"A lot of user organizations do a great job of scanning the code they put on their own sites, but they may not scan the code they're posting from third parties," Daswani warned. "The marketing people will add an ad or a widget to a site, and the IT people may not vet it before it's posted."

Many well-known sites are infected by malware, and the most popular sites are generally targeted most frequently, Daswani noted. In the past two years, major government sites, such as the Treasury Department and Environmental Protection Agency, have been infected, causing them to serve up drive-by downloads to their users. The National Institute of Health has been infected five times in the past two years, and the state of Alabama's website has been infected 37 times in that same time period, he reported.

"It's time to recognize that this is the method of choice for many distributors of malware," Daswani said.

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.

Tim Wilson is Editor in Chief and co-founder of Dark Reading.com, UBM Tech's online community for information security professionals. He is responsible for managing the site, assigning and editing content, and writing breaking news stories. Wilson has been recognized as one ... View Full Bio

 

Recommended Reading:

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
COVID-19: Latest Security News & Commentary
Dark Reading Staff 8/10/2020
Pen Testers Who Got Arrested Doing Their Jobs Tell All
Kelly Jackson Higgins, Executive Editor at Dark Reading,  8/5/2020
Researcher Finds New Office Macro Attacks for MacOS
Curtis Franklin Jr., Senior Editor at Dark Reading,  8/7/2020
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Current Issue
Special Report: Computing's New Normal, a Dark Reading Perspective
This special report examines how IT security organizations have adapted to the "new normal" of computing and what the long-term effects will be. Read it and get a unique set of perspectives on issues ranging from new threats & vulnerabilities as a result of remote working to how enterprise security strategy will be affected long term.
Flash Poll
The Changing Face of Threat Intelligence
The Changing Face of Threat Intelligence
This special report takes a look at how enterprises are using threat intelligence, as well as emerging best practices for integrating threat intel into security operations and incident response. Download it today!
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2020-17478
PUBLISHED: 2020-08-10
ECDSA/EC/Point.pm in Crypt::Perl before 0.33 does not properly consider timing attacks against the EC point multiplication algorithm.
CVE-2020-15648
PUBLISHED: 2020-08-10
Using object or embed tags, it was possible to frame other websites, even if they disallowed framing using the X-Frame-Options header. This vulnerability affects Thunderbird < 78 and Firefox < 78.0.2.
CVE-2020-15649
PUBLISHED: 2020-08-10
Given an installed malicious file picker application, an attacker was able to steal and upload local files of their choosing, regardless of the actually files picked. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox ESR...
CVE-2020-15650
PUBLISHED: 2020-08-10
Given an installed malicious file picker application, an attacker was able to overwrite local files and thus overwrite Firefox settings (but not access the previous profile). *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Fir...
CVE-2020-15651
PUBLISHED: 2020-08-10
A unicode RTL order character in the downloaded file name can be used to change the file's name during the download UI flow to change the file extension. This vulnerability affects Firefox for iOS < 28.