The name “Predator the Thief” denotes that this type of malware is used by attackers to stealthily collect information from vulnerable victims’ machines and also to monitor clipboard activities.

The first attack of Predator was observed in Russia in July of 2018. Predator’s malware author has been maintaining the telegram profile named “@sett9” to distribute Predator from the very beginning until now. However, the malware author has been constantly updating and releasing new versions of the malware to avoid being detected by security products.

We have observed a few changes in the latest version (3.3.2) of this malware, which will be the topic of interest for this blog.

In this version, the stealer came with a double extension “.mp4.scr” file, which was actually a PE file. 

Figure 1: Predator malware with double extension

Also, the stealer was digitally signed by an anonymous signer ‘furniture percent’. However, the signature was not valid. Moreover, the previous versions of this malware were not digitally signed.

Figure 2: Invalid digital signature

We also noticed that this version of the malware is also using process injection to elevate its privileges and evade detection from security products as its predecessors. The sample under investigation on execution chose dllhost.exe for injection.

Figure 3: dllhost.exe process injection

It then creates a mutant under dllhost.exe in order to retrieve information like browser history, cookies, etc.

Figure 4: Mutants created by dllhost.exe

The predator has its C&C servers hosted mostly in Russia.

Figure 5: HTTP/POST request to malicious domain using dllhost.exe

Some of the information that is stolen from the user are:

  • Cookies
  • Browser History
  • Peripheral device information
  • Wallet details such as Ethereum, bitcoin etc.
  • Card details
  • Installed software
  • Hardware information
  • Logical drives
  • IP address
  • One or two files from FileZilla, WinFtp, etc.
  • Social networking credentials from Discord, Telegram, Steam, etc.
Figure 6: User credentials and other information in archive format
Figure 7: Contents in t2t2v1y3q8t2v1y3q8.zip archive

The latest version of the “Predator the Thief” is version 3.3.2.

Figure 8: User details sent in Information.txt

Analysis of AutoIt script

Unlike in previous versions of Predator, the attacker has used AutoIt script from version 3 onwards. 

Decompiling the PE file, video_2019_11_05_17_23_18.mp4.scr, resulted in an obfuscated AutoIt script. This AutoIt script had many junk variable declarations and junk functions as shown in Figure 9.

Figure 9: Obfuscated AutoIt script

The deobfuscated script containing the code to create an autostart entry is as shown below.

Figure 10: Deobfuscated script

It also carries a list of system processes which are the targets for process injection. It uses these processes for extracting system information.

Figure 11: Targeted process for injection

The script has a hardcoded value to choose from the list of target processes (for injection). Here in our case, the script opts for dllhost.exe by passing argument ‘8’.

Figure 12: Arguments passed for process selection

This vmaware malware checks if it is running within a VM and if yes, it terminates itself from execution. Anti-VM techniques are used by this malware to thwart any attempts of analysis by researchers.

Figure 13: Anti-VM technique used by Predator

It checks for the OS version, to choose appropriate actions for bypassing UAC.

Figure 14: OS version check

Stealer sets the value of HKCU\Software\Classes\mscfile\shell\open\command to itself, thereby executing the stealer process. This malware uses the system processes fodhelper in Windows 10 and event viewer in Windows 7 & 8 to bypass User Account Control (UAC) and have escalated privileges (administrative rights) to carry out its malicious behaviour.

Figure 15: Bypassing UAC

As shown in Figures 16, 17 & 18 below, this script contains obfuscated code which after de-obfuscation results in a decryption loop and the VirtualAlloc( ) function for executing the decrypted code in memory. This decrypted code is then injected into dllhost.exe.

Figure 16: Shellcode found in script
Figure 17: Virtual Alloc API
Figure 18: XOR decryption loop

Analysis of another sample from the same version of Predator

Our second sample (E3B3A7AC3B184AAFCB003C84CF51A6BE) under analysis used fodhelper.exe to bypass UAC.

Figure 19: Process tree for a different sample from the same version

Here, the malware opts for Regsvcs.exe for injection by passing argument ‘4’.

Figure 20: Target process selection

This malware creates a startup entry by dropping files in the following locations:

  • C:\Users\%user%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\btpanui.url
  • C:\Users\%user%\btpanui\btpanui.vbs
  • C:\Users\%user%\btpanui\hvsievaluator.exe

“btpanui.url” dropped by this malware in the Startup location points to “btpanui.vbs” and is executed on every restart of the machine.

Figure 21: Autostart entry using btpanui.url

The malware self-copies into the user folder as “hvsievaluator.exe” and drops “btpanui.vbs” as shown below.

Figure 22: Contents in user folder

btpanui.vbs in turn executes hvsievaluator.exe.

Figure 23: Contents in btpanui.vbs

As in the previous sample, this sample also sets the registry value for HKCU/Software/Classes/ms-settings/shell/open/command key to its own process for attaining privilege escalation and for bypassing the UAC, as mentioned in Figure 15. 

Figure 24: Privilege Escalation

Let’s wait for the next version of Predator and see what other changes have been made to attack users and to stay under the radar. Users are advised to apply OS security patches regularly and install a reputed security product like K7 Total Security to stay protected. It’s always better to be safe than losing your valuable credentials.

Indicators of Compromise (IOCs) 

HashDetection Name
6D3C86C2B65B1B05F4A019CC1F3B1664 Riskware ( 0040eff71 )
E3B3A7AC3B184AAFCB003C84CF51A6BE  Trojan ( 0055be371 )

C&C

vochspak[.]su

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