Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Malware & Threats

Fifth Tinba Variant Targets Financial Entities in Asia Pacific

A new variant of the Tinba malware has emerged on the threat landscape and is targeting financial entities in the Asia Pacific region, researchers at F5 Networks warn.

A new variant of the Tinba malware has emerged on the threat landscape and is targeting financial entities in the Asia Pacific region, researchers at F5 Networks warn.

According to F5’s report, the new malware variant, called Tinbapore, was initially detected in November 2015 and has already put millions of dollars at risk.

The threat was found to include a series of changes and now creates its own instance of explorer.exe that runs in the background.

Tinba, also known as Tinybanker, Zusy, and HμNT€R$, is a banking Trojan that has been around since May 2012, mainly used to target users in the Europe, Middle East, and Africa (EMEA) region and in the Americas. The malware was mainly noticed for its very small size, at around 20 KB including all Webinjects and configuration.

Tinba was discovered using four system libraries during runtime, namely ntdll.dll, advapi32.dll, ws2_32.dll, and user32.dll. It was designed to hook all browsers on an infected machine ad can intercept HTTP requests and to perform web injections.

As F5 Networks researchers explain in their report, the malware has evolved since first spotted, with new and improved variants employing a domain generation algorithm (DGA) that allowed them to achieve persistency. The functionality made it possible for the Trojan to return to life even after a command and control (C&C) server was taken down.

The new variant, Tinbapore, is said to spread through spam emails and to continue stealing login credentials and inject malicious HTML/JavaScrip code into the user’s browser. Once the stolen information is sent to the C&C server, the attacker can use the stolen information to engage into fraudulent activities, including unauthorized transactions and the use of stolen credit cards.

Once the targeted user opens the malicious email and executes the malware, Tinbapore opens the winver.exe process, injects itself into it, and then propagates to explorer.exe. Then, the malware writes itself as a bin.exe file into the Application Data folder with a randomly generated subfolder and hooks into several functions inside the ntdll.dll library, such as NtCreateProcessEx, NtCreateThread, NtEnumerateValueKey, NtQueryDirectoryFile, and NtResumeThread.

Advertisement. Scroll to continue reading.

To achieve persistence on the infected system, the malware writes two auto-run locations, so that it starts at Windows boot up. When the user launches a browser, malware also injects itself into the process and hooks a series of wininet.dll library functions, which allows it to perform browser injections. Furthermore, it lowers the security settings and sets the DisplayMixedContentInternet option to zero (0), providing attackers with the possibility to perform browser injections without prompting the user.

The security researchers also note that the malware is a rootkit, which means that it hooks system functions to gain higher system privileges than the user. 

Tinbapore includes an Automatic Transfer Systems (ATS) engine injection management system through which it injects content into the victim’s browser and sends the logged information back to the ATS server. The injected script, which is usually a message informing users that the resource they were trying to access was not available, is then deleted to cover the malware’s tracks.

According to F5 Networks, 30 percent of the institutions targeted by the new malware variant are located in Singapore. However, organizations attacked by the Trojan are not located only in the Asia Pacific region (although 70 percent of them are), but users in EMEA (15 percent) and the Americas (15 percent) are also at risk.

The source code for Tinba emerged online in July 2014 (), and new and improved variants of the malware have been observed ever since. In June last year, the banking malware was spotted targeting customers of European financial institutions, while Abuse.ch, a Swiss security site that tracks malware campaigns, revealed in November that the Trojan was targeting mainly users in Russia and Poland.

Written By

Click to comment

Trending

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Understand how to go beyond effectively communicating new security strategies and recommendations.

Register

Join us for an in depth exploration of the critical nature of software and vendor supply chain security issues with a focus on understanding how attacks against identity infrastructure come with major cascading effects.

Register

Expert Insights

Related Content

Cybercrime

The changing nature of what we still generally call ransomware will continue through 2023, driven by three primary conditions.

Cybercrime

A recently disclosed vBulletin vulnerability, which had a zero-day status for roughly two days last week, was exploited in a hacker attack targeting the...

Malware & Threats

The NSA and FBI warn that a Chinese state-sponsored APT called BlackTech is hacking into network edge devices and using firmware implants to silently...

Application Security

Virtualization technology giant VMware on Tuesday shipped urgent updates to fix a trio of security problems in multiple software products, including a virtual machine...

Malware & Threats

Unpatched and unprotected VMware ESXi servers worldwide have been targeted in a ransomware attack exploiting a vulnerability patched in 2021.

Cyberwarfare

An engineer recruited by intelligence services reportedly used a water pump to deliver Stuxnet, which reportedly cost $1-2 billion to develop.

Malware & Threats

Apple’s cat-and-mouse struggles with zero-day exploits on its flagship iOS platform is showing no signs of slowing down.

Cybercrime

No one combatting cybercrime knows everything, but everyone in the battle has some intelligence to contribute to the larger knowledge base.