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.

Attacks/Breaches

2/21/2019
05:50 PM
Connect Directly
Twitter
RSS
E-Mail
50%
50%

Attack Campaign Experiments with Rapid Changes in Email Lure Content

It's like polymorphic behavior - only the changes are in the email lures themselves, with randomized changes to headers, subject lines, and body content.

A new email Trojan campaign spotted by security researchers has added another twist in evasive attacker behavior: Researchers with GreatHorn report that the waves of attacks they've observed since yesterday afternoon are rapidly randomizing the email content characteristics of their lures.

"Masquerading as a confirmation on a paid invoice, the attack is sophisticated in that it lacks the consistency of a typical volumetric attack, making it more challenging for email security tools to identify and block," says E.J. Whaley, solutions engineer at GreatHorn. 

Attackers have long leaned on metamorphic and polymorphic malware techniques to make swift changes to the code in order to evade detection. It was only a matter of time before they started taking that philosophy to the scam delivery vehicles. This method is in contrast to what Whaley says is typical in most Trojan phishing email lures, where they'll stick to a single pattern with "slight customizations." Instead, these attacks are switching up subject lines, email content, email addresses, display name spoofs, and destination URLs. 

"Body content generally follows a pattern that confirms the receipt of a payment for an invoice but uses slightly different language to evade capture," Whaley says.

While the subject lines vary, they all seem to cluster around references to receipts or invoices. Sometimes the attacks are very targeted — using spoofed names of a fellow employee of the target — and sometimes they use random names, sent from numerous compromised email accounts. The bulk of the compromise accounts are coming from South American companies. 

The attackers are trying to trick users into downloading a Word template with a VBA downloader trojan embedded within. GreatHorn says the attack was detected in about one in 10 accounts in its user base.

Paid invoice attacks like these are increasingly at the top of phishers’ playbooks. Last year six of 10 phishing messages used some variation of "invoice" as its subject.

Related Content:

 

 

Join Dark Reading LIVE for two cybersecurity summits at Interop 2019. Learn from the industry's most knowledgeable IT security experts. Check out the Interop agenda here.

Ericka Chickowski specializes in coverage of information technology and business innovation. She has focused on information security for the better part of a decade and regularly writes about the security industry as a contributor to Dark Reading.  View Full Bio
 

Recommended Reading:

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
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 Threat from the Internetand What Your Organization Can Do About It
The Threat from the Internetand What Your Organization Can Do About It
This report describes some of the latest attacks and threats emanating from the Internet, as well as advice and tips on how your organization can mitigate those threats before they affect your business. Download it today!
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2020-5615
PUBLISHED: 2020-08-04
Cross-site request forgery (CSRF) vulnerability in [Calendar01] free edition ver1.0.0 and [Calendar02] free edition ver1.0.0 allows remote attackers to hijack the authentication of administrators via unspecified vectors.
CVE-2020-5616
PUBLISHED: 2020-08-04
[Calendar01], [Calendar02], [PKOBO-News01], [PKOBO-vote01], [Telop01], [Gallery01], [CalendarForm01], and [Link01] [Calendar01] free edition ver1.0.0, [Calendar02] free edition ver1.0.0, [PKOBO-News01] free edition ver1.0.3 and earlier, [PKOBO-vote01] free edition ver1.0.1 and earlier, [Telop01] fre...
CVE-2020-5617
PUBLISHED: 2020-08-04
Privilege escalation vulnerability in SKYSEA Client View Ver.12.200.12n to 15.210.05f allows an attacker to obtain unauthorized privileges and modify/obtain sensitive information or perform unintended operations via unspecified vectors.
CVE-2020-11583
PUBLISHED: 2020-08-03
A GET-based XSS reflected vulnerability in Plesk Obsidian 18.0.17 allows remote unauthenticated users to inject arbitrary JavaScript, HTML, or CSS via a GET parameter.
CVE-2020-11584
PUBLISHED: 2020-08-03
A GET-based XSS reflected vulnerability in Plesk Onyx 17.8.11 allows remote unauthenticated users to inject arbitrary JavaScript, HTML, or CSS via a GET parameter.