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
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

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Where Businesses Waste Endpoint Security Budgets
Kelly Sheridan, Staff Editor, Dark Reading,  7/15/2019
US Mayors Commit to Just Saying No to Ransomware
Robert Lemos, Contributing Writer,  7/16/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Current Issue
Building and Managing an IT Security Operations Program
As cyber threats grow, many organizations are building security operations centers (SOCs) to improve their defenses. In this Tech Digest you will learn tips on how to get the most out of a SOC in your organization - and what to do if you can't afford to build one.
Flash Poll
The State of IT Operations and Cybersecurity Operations
The State of IT Operations and Cybersecurity Operations
Your enterprise's cyber risk may depend upon the relationship between the IT team and the security team. Heres some insight on what's working and what isn't in the data center.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2002-0390
PUBLISHED: 2019-07-21
** REJECT ** DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: CVE-2002-0639. Reason: This candidate is a reservation duplicate of CVE-2002-0639. Notes: All CVE users should reference CVE-2002-0639 instead of this candidate. All references and descriptions in this candidate have been removed to prevent ...
CVE-2018-17210
PUBLISHED: 2019-07-20
An issue was discovered in PrinterOn Central Print Services (CPS) through 4.1.4. The core components that create and launch a print job do not perform complete verification of the session cookie that is supplied to them. As a result, an attacker with guest/pseudo-guest level permissions can bypass t...
CVE-2019-12934
PUBLISHED: 2019-07-20
An issue was discovered in the wp-code-highlightjs plugin through 0.6.2 for WordPress. wp-admin/options-general.php?page=wp-code-highlight-js allows CSRF, as demonstrated by an XSS payload in the hljs_additional_css parameter.
CVE-2019-9229
PUBLISHED: 2019-07-20
An issue was discovered on AudioCodes Mediant 500L-MSBR, 500-MBSR, M800B-MSBR and 800C-MSBR devices with firmware versions F7.20A to F7.20A.251. An internal interface exposed to the link-local address 169.254.254.253 allows attackers in the local network to access multiple quagga VTYs. Attackers can...
CVE-2019-12815
PUBLISHED: 2019-07-19
An arbitrary file copy vulnerability in mod_copy in ProFTPD up to 1.3.5b allows for remote code execution and information disclosure without authentication, a related issue to CVE-2015-3306.