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.

ABTV //

Malware

6/1/2018
09:35 AM
Larry Loeb
Larry Loeb
Larry Loeb
50%
50%

BackSwap Banking Trojan Shows How Malware Evolves

The newly discovered BackSwap baking Trojan is designed to avoid the security protections that vendors and businesses have created to stop these types of malware attacks.

While attention has increased on newer malware, such as cryptomining and ransomware, older types of malicious software and the attackers behind them have been quietly updating the different ways that they can evade detection.

A malware banker Trojan named BackSwap has been observed by Michal Poslusny of ESET that functions in a unique manner.

Most major banking trojans -- Dridex, Ursnif, Zbot, Trickbot, Qbot -- have used injection of malicious code inside the browser's processes to do their stealing.

This lead the antivirus product makers to scan for process injection attempts by malware, and they have become good at recognizing these types of attacks.

Browser makers also made it harder for malware to infect a page's content if such injections were successful.

These efforts made usual techniques less effective, and in need of tweaks in response to every browser update.

Now, BackSwap has come up with three different techniques to bypass all of this.

The first is that the malware hooks key window message loop events that exist inside of Microsoft Windows in order to inspect values of the window objects for banking activity. This is done by searching for URL-like patterns, such as "https" strings, as well as other terms that can be related to a bank's name.

The Trojan then springs into action when it finds the user loading bank sites. The action it takes is not code injection, rather it is a simulation of a key press.

One technique the Trojan uses will simulate the key presses necessary to open the browser’s developer console. Information is then "typed" into the console to give the attacker control of what the user sees. The browser window is also made invisible during this process and it might seem to a user that their browser simply froze for a moment. This keeps the user unaware that an attack is in progress.

There is another technique some malware variants use.

The malicious script is executed directly from the address bar, through JavaScript protocol URLs. The bar that is brought up -- "javascript" -- is first "typed" in, the malware script is then "pasted" in, and then is executed by "pressing" the return key. At the end of the process, the address bar is cleared removing any trace of the compromise.

ESET research finds that the attack works on Google Chrome, Mozilla Firefox and Internet Explorer, but that other browsers could be included with tweaks to the malware.


Now entering its fifth year, the 2020 Vision Executive Summit is an exclusive meeting of global CSP executives focused on navigating the disruptive forces at work in telecom today. Join us in Lisbon on December 4-6 to meet with fellow experts as we define the future of next-gen communications and how to make it profitable.

For right now, BackSwap has support for altering the web portals of only five Polish banks -- PKO Bank Polski, Bank Zachodni WBK S.A., mBank, ING and Pekao. It seems only a matter of time before this kind of malware spreads to other banks, since the technique is so stealthy and so effective.

ESET notes that: "We have notified the affected browser vendors about the innovative script injection technique." That' s good, because the malware takes specific steps to avoid the safeguards that security pros have already put in place to stop automated pasting into developer consoles and status bars.

Security is always a back and forth effort. The good guys try to mitigate, and the malwarers always come up with something new to get around them.

Related posts:

— Larry Loeb has written for many of the last century's major "dead tree" computer magazines, having been, among other things, a consulting editor for BYTE magazine and senior editor for the launch of WebWeek.

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.