CYBER NEWS

Rio Malware 2016: Trojan-Proxy.PowerShell.Agent.a

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Besides ransomware, this month has seen some older banking Trojans equipped with new variants as well as completely new pieces. The latest banking Trojan that has been lurking around uses Microsoft PowerShell to change the victim’s PC local proxy settings to redirect users to another server while attempting to access a banking portal. Kaspersky researchers have detected the Trojan as Trojan-Proxy.PowerShell.Agent.a.


Trojan-Proxy.PowerShell.Agent.a: Technical Overview

Crooks are always creating new ways to improve the malware they use to target bank accounts, and now Brazilian attackers have made an important addition to their arsenal: the use of PowerShell, Kaspersky researchers point out.

Brazil is the most infected country worldwide in terms of banking Trojans, according to Kaspersky’s Q1 2016 report, so it’s not surprising that the quality of malware is evolving. The research team was able to “catch” Trojan-Proxy.PowerShell.Agent.a in the wild a few days ago, marking a new achievement by Brazil’s cyber criminals.

This is not the first time of banking Trojans hijacking computer proxy settings. However, in previous campaigns attackers have used local PAC, or Proxy Auto-Config. In addition, the Trojan also uses PowerShell.

What Is PowerShell?

PowerShell is a task automation and configuration management framework from Microsoft, consisting of a command-line shell and associated scripting language built on the .NET Framework. The utility was recently open-sourced and is now available for Linux and Mac.


Trojan-Proxy.PowerShell.Agent.a Distribution Path

The Trojan is spread via an email campaign, and is a masqueraded as a receipt from a mobile operator in a malicious .PIF file. Once executed, the file would chance the proxy configuration in Internet Explorer to a malicious proxy server to redirect connections to phishing pages for Brazilian banks.

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Interestingly, the Trojan doesn’t employ a command & control communication:

After execution it spawned the process “powershell.exe” with the command line “-ExecutionPolicy Bypass -File %TEMP%\599D.tmp\599E.ps1” aiming to bypass PowerShell execution policies. The .ps1 file in the temp folder uses random names. It’s a base64 encoded script capable of making changes in the system.

Because other apps that don’t have a built-in proxy handler use this configuration, proxy settings are crucial. Furthermore, popular browsers except Firefox employ the proxy settings of Internet Explorer as their default Internet connection settings, which makes things worse for users.

In other words, whenever the user attempts to access a banking portal through one of the affected browsers, the HTTP request will be intercepted and redirected to the malicious server. The user will be redirected to a fake banking portal that harvests his banking credentials.


Trojan-Proxy.PowerShell.Agent.a: Targets

For now, the banking Trojan only targets banks in Brazil but researchers expect the campaign to move to other countries as the end of the Olympic Games is near. Currently the malware is specifically targeting machines whose default language is Brazilian Portuguese, or PTBR.

Other banking Trojans to keep away from:


Trojan-Proxy.PowerShell.Agent.a: Removal and Protection

Infected users should immediately remove the Trojan from their systems. The best way to do so is automatically, via a powerful anti-spyware program.

Automatically remove Trojan-Proxy.PowerShell.Agent.a by downloading an advanced anti-malware program

1. Remove Trojan-Proxy.PowerShell.Agent.a with SpyHunter Anti-Malware Tool

Remove Trojan-Proxy.PowerShell.Agent.a with SpyHunter Anti-Malware Tool

1. Install SpyHunter to scan for and remove Trojan-Proxy.PowerShell.Agent.a.2. Scan with SpyHunter to Detect and Remove Trojan-Proxy.PowerShell.Agent.a.
Step 1:Click on the “Download” button to proceed to SpyHunter’s download page.

It is highly recommended to run a scan before purchasing the full version of the software to make sure that the current version of the malware can be detected by SpyHunter.

Step 2: Guide yourself by the download instructions provided for each browser.
Step 3: After you have installed SpyHunter, wait for it to automatically update.

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Step1: After the update process has finished, click on the ‘Scan Computer Now’ button.
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Step2: After SpyHunter has finished scanning your PC for any Trojan-Proxy.PowerShell.Agent.a files, click on the ‘Fix Threats’ button to remove them automatically and permanently.
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Step3: Once the intrusions on your PC have been removed, it is highly recommended to restart it.

2. Back up your data to secure it against infections and file encryption by Trojan-Proxy.PowerShell.Agent.a in the future

Back up your data to secure it against attacks in the future

IMPORTANT! Before reading the Windows backup instructions, we highly recommend to back up your data automatically with cloud backup and insure it against any type of data loss on your device, even the most severe. We recommend reading more about and downloading SOS Online Backup .

To back up your files via Windows and prevent any future intrusions, follow these instructions:

1. For Windows 7 and earlier 1. For Windows 8, 8.1 and 10 1. Enabling the Windows Defense Feature (Previous Versions)

1-Click on Windows Start Menu
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2-Type Backup And Restore
3-Open it and click on Set Up Backup
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4-A window will appear asking you where to set up backup. You should have a flash drive or an external hard drive. Mark it by clicking on it with your mouse then click on Next.
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5-On the next window, the system will ask you what do you want to backup. Choose the ‘Let Me Choose’ option and then click on Next.
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6-Click on ‘Save settings and run backup’ on the next window in order to protect your files from possible attacks by Trojan-Proxy.PowerShell.Agent.a.
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1-Press Windows button + R
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2-In the window type ‘filehistory’ and press Enter
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3-A File History window will appear. Click on ‘Configure file history settings’
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4-The configuration menu for File History will appear. Click on ‘Turn On’. After its on, click on Select Drive in order to select the backup drive. It is recommended to choose an external HDD, SSD or a USB stick whose memory capacity is corresponding to the size of the files you want to backup.
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5-Select the drive then click on ‘Ok’ in order to set up file backup and protect yourself from Trojan-Proxy.PowerShell.Agent.a.

1- Press Windows button + R keys.
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2- A run windows should appear. In it type ‘sysdm.cpl’ and then click on Run.
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3- A System Properties windows should appear. In it choose System Protection.
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5- Click on Turn on system protection and select the size on the hard disk you want to utilize for system protection.
6- Click on Ok and you should see an indication in Protection settings that the protection from Trojan-Proxy.PowerShell.Agent.a is on.
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Restoring a file via Windows Defense feature:
1-Right-click on the encrypted file, then choose Properties.
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2-Click on the Previous Versions tab and then mark the last version of the file.
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3-Click on Apply and Ok and the file encrypted by Trojan-Proxy.PowerShell.Agent.a should be restored.

3. Restore files encrypted by Trojan-Proxy.PowerShell.Agent.a

Restore Files Encrypted by Trojan-Proxy.PowerShell.Agent.a

Security engineers strongly advise users NOT to pay the ransom money and attempt restoring the files using other methods. Here are several suggestions:

To restore your data, your first bet is to check again for shadow copies in Windows using this software:

Shadow Explorer

If this method does not work, Kaspersky have provided a decryptors for files encrypted with the this and other encryption algorithms:

Kaspersky Decryptors

Another method of restoring your files is by trying to bring back your files via data recovery software. Here are some examples of data recovery programs:

There is also the technical option to use a network sniffer:

Another way to decrypt the files is by using a Network Sniffer to get the encryption key, while files are encrypted on your system. A Network Sniffer is a program and/or device monitoring data traveling over a network, such as its internet traffic and internet packets. If you have a sniffer set before the attack happened you might get information about the decryption key.

Optional: Using Alternative Anti-Malware Tools

Remove Trojan-Proxy.PowerShell.Agent.a Using Other Alternative Tools

STOPZilla Anti Malware
1. Download and Install STOPZilla Anti-malware to Scan for And Remove Trojan-Proxy.PowerShell.Agent.a.
Step 1: Download STOPZilla by clicking here.
Step 2: A pop-up window will appear. Click on the ‘Save File’ button. If it does not, click on the Download button and save it afterwards.
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Step 3: After you have downloaded the setup, simply open it.
Step 4: The installer should appear. Click on the ‘Next’ button.
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Step 5: Check the ‘I accept the agreement’ check circle if not checked if you accept it and click the ‘Next’ button once again.
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Step 6: Review and click on the ‘Install’ button.
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Step 7: After the installation process has completed click on the ‘Finish’ button.

2. Scan your PC with STOPZilla Anti Malware to remove all Trojan-Proxy.PowerShell.Agent.a associated files completely.
Step 1: Launch STOPZilla if you haven’t launched it after install.
Step 2: Wait for the software to automatically scan and then click on the ‘Repair Now’ button. If it does not scan automatically, click on the ‘Scan Now’ button.
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Step 3: After the removal of all threats and associated objects, you should Restart your PC.

Milena Dimitrova

Milena Dimitrova

An inspired writer and content manager who has been with SensorsTechForum since the beginning. Focused on user privacy and malware development, she strongly believes in a world where cybersecurity plays a central role. If common sense makes no sense, she will be there to take notes. Those notes may later turn into articles! Follow Milena @Milenyim

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1 Comment

  1. AvatarBonny

    I use proxy and have no problem with trojans.

    Reply

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