Analysis by: Jay Garcia
ALIASES:

HEUR:AdWare.Win32.Vosteran.heur (Kaspersky); PUA.Gen.2 (Norton)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Potentially Unwanted Application

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This Potentially Unwanted Application arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It does not have any propagation routine.

It does not have any backdoor routine.

It does not have any information-stealing capability.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size: 775,749 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 04 Jul 2019
Payload: Connects to URLs/IPs, Displays windows

Arrival Details

This Potentially Unwanted Application arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Potentially Unwanted Application drops the following files:

  • %User Temp%\000{random characters}.log
  • %User Temp%\ish{random numbers}\css\ie6_main.css
  • %User Temp%\ish{random numbers}\css\main.css
  • %User Temp%\ish{random numbers}\css\sdk-ui\browse.css
  • %User Temp%\ish{random numbers}\css\sdk-ui\button.css
  • %User Temp%\ish{random numbers}\css\sdk-ui\checkbox.css
  • %User Temp%\ish{random numbers}\css\sdk-ui\images\button-bg.png
  • %User Temp%\ish{random numbers}\css\sdk-ui\images\progress-bg-corner.png
  • %User Temp%\ish{random numbers}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\ish{random numbers}\css\sdk-ui\images\progress-bg2.png
  • %User Temp%\ish{random numbers}\css\sdk-ui\progress-bar.css
  • %User Temp%\ish{random numbers}\csshover3.htc
  • %User Temp%\ish{random numbers}\fciv.exe
  • %User Temp%\ish{random numbers}\form.bmp.Mask
  • %User Temp%\ish{random numbers}\images\BG.png
  • %User Temp%\ish{random numbers}\images\Close.png
  • %User Temp%\ish{random numbers}\images\Close_Hover.png
  • %User Temp%\ish{random numbers}\images\Color_Button.png
  • %User Temp%\ish{random numbers}\images\Color_Button_Hover.png
  • %User Temp%\ish{random numbers}\images\Grey_Button.png
  • %User Temp%\ish{random numbers}\images\Grey_Button_Hover.png
  • %User Temp%\ish{random numbers}\images\Icon_Generic.png
  • %User Temp%\ish{random numbers}\images\Loader.gif
  • %User Temp%\ish{random numbers}\images\Pause_Button.png
  • %User Temp%\ish{random numbers}\images\Progress.png
  • %User Temp%\ish{random numbers}\images\ProgressBar.png
  • %User Temp%\ish{random numbers}\images\Quick_Specs.png
  • %User Temp%\ish{random numbers}\images\Resume_Button.png
  • %User Temp%\ish{random numbers}\images\sponsored.png
  • %User Temp%\ish{random numbers}\images\step01.png
  • %User Temp%\ish{random numbers}\images\step02.png
  • %User Temp%\ish{random numbers}\images\step03.png
  • %User Temp%\ish{random numbers}\images\step04.png
  • %User Temp%\ish{random numbers}\locale\DE.locale
  • %User Temp%\ish{random numbers}\locale\EN.locale
  • %User Temp%\ish{random numbers}\locale\ES.locale
  • %User Temp%\ish{random numbers}\locale\FR.locale
  • %User Temp%\ish{random numbers}\locale\JA.locale
  • %User Temp%\ish{random numbers}\locale\PL.locale
  • %User Temp%\ish{random numbers}\locale\PT.locale
  • %User Temp%\ish{random numbers}\locale\RU.locale
  • %User Temp%\ish{random numbers}\bootstrap_32596.html
  • %User Temp%\is{random numbers}\7424B7EA_stp.DAT
  • %User Temp%\is{random numbers}\7424B7EA_stp.DAT.part
  • %User Temp%\ICReinstall_{malware filename}.exe
  • %Desktop%\Continue FileZilla Installation.lnk

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\Desktop on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It creates the following folders:

  • %User Temp%\ish{random numbers}\css\
  • %User Temp%\ish{random numbers}\css\sdk-ui
  • %User Temp%\ish{random numbers}\css\sdk-ui\images
  • %User Temp%\ish{random numbers}\images
  • %User Temp%\ish{random numbers}\locale
  • %User Temp%\is{random numbers}

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Propagation

This Potentially Unwanted Application does not have any propagation routine.

Backdoor Routine

This Potentially Unwanted Application does not have any backdoor routine.

Information Theft

This Potentially Unwanted Application does not have any information-stealing capability.

Other Details

This Potentially Unwanted Application connects to the following website to send and receive information:

  • http://rp.{BLOCKED}forgecdn.com/?pcrc={CRC value}&v={version}
  • http://os2.{BLOCKED}forgecdn.com/SourceForge_FLZ/?v={version}&c=942370647
  • http://os.{BLOCKED}forgecdn.com/SourceForge_FLZ/?v={version}&c=942370647

It does the following:

  • It displays the following during installation:

  • Connects to the following URL to download installer-related files:
    • http://do{BLOCKED}.sourc{BLOCKED}e.net/project/filez{BLOCKED}la%20Server/0.9.49/FileZilla_Server-0_9_49.exe?r=http%3A%2F%2F{BLOCKED}cts%2Fsfnet_filezilla%2Fdownloads%2FFileZilla%2520Ser{BLOCKED}%2FFileZilla_Server-0_9_49.e{BLOCKED}15964&use_mirror=jaist&secret=fdcca4c49ed1{BLOCKED}8f475cb3a04bc04d3a708ff03be9cf6

NOTES:

Rootkit Capabilities

This Potentially Unwanted Application does not have rootkit capabilities.

This Potentially Unwanted Application does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.850
SSAPI PATTERN File: 2.190.08
SSAPI PATTERN Date: 04 Jul 2019

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 2

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %User Temp%\000{random characters}.log
  • %User Temp%\ish{random numbers}\css\ie6_main.css
  • %User Temp%\ish{random numbers}\css\main.css
  • %User Temp%\ish{random numbers}\css\sdk-ui\browse.css
  • %User Temp%\ish{random numbers}\css\sdk-ui\button.css
  • %User Temp%\ish{random numbers}\css\sdk-ui\checkbox.css
  • %User Temp%\ish{random numbers}\css\sdk-ui\images\button-bg.png
  • %User Temp%\ish{random numbers}\css\sdk-ui\images\progress-bg-corner.png
  • %User Temp%\ish{random numbers}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\ish{random numbers}\css\sdk-ui\images\progress-bg2.png
  • %User Temp%\ish{random numbers}\css\sdk-ui\progress-bar.css
  • %User Temp%\ish{random numbers}\csshover3.htc
  • %User Temp%\ish{random numbers}\fciv.exe
  • %User Temp%\ish{random numbers}\form.bmp.Mask
  • %User Temp%\ish{random numbers}\images\BG.png
  • %User Temp%\ish{random numbers}\images\Close.png
  • %User Temp%\ish{random numbers}\images\Close_Hover.png
  • %User Temp%\ish{random numbers}\images\Color_Button.png
  • %User Temp%\ish{random numbers}\images\Color_Button_Hover.png
  • %User Temp%\ish{random numbers}\images\Grey_Button.png
  • %User Temp%\ish{random numbers}\images\Grey_Button_Hover.png
  • %User Temp%\ish{random numbers}\images\Icon_Generic.png
  • %User Temp%\ish{random numbers}\images\Loader.gif
  • %User Temp%\ish{random numbers}\images\Pause_Button.png
  • %User Temp%\ish{random numbers}\images\Progress.png
  • %User Temp%\ish{random numbers}\images\ProgressBar.png
  • %User Temp%\ish{random numbers}\images\Quick_Specs.png
  • %User Temp%\ish{random numbers}\images\Resume_Button.png
  • %User Temp%\ish{random numbers}\images\sponsored.png
  • %User Temp%\ish{random numbers}\images\step01.png
  • %User Temp%\ish{random numbers}\images\step02.png
  • %User Temp%\ish{random numbers}\images\step03.png
  • %User Temp%\ish{random numbers}\images\step04.png
  • %User Temp%\ish{random numbers}\locale\DE.locale
  • %User Temp%\ish{random numbers}\locale\EN.locale
  • %User Temp%\ish{random numbers}\locale\ES.locale
  • %User Temp%\ish{random numbers}\locale\FR.locale
  • %User Temp%\ish{random numbers}\locale\JA.locale
  • %User Temp%\ish{random numbers}\locale\PL.locale
  • %User Temp%\ish{random numbers}\locale\PT.locale
  • %User Temp%\ish{random numbers}\locale\RU.locale
  • %User Temp%\ish{random numbers}\bootstrap_32596.html
  • %User Temp%\is{random numbers}\7424B7EA_stp.DAT
  • %User Temp%\is{random numbers}\7424B7EA_stp.DAT.part
  • %User Temp%\ICReinstall_{malware filename}.exe
  • %Desktop%\Continue FileZilla Installation.lnk

Step 4

Scan your computer with your Trend Micro product to delete files detected as PUA.Win32.InstallCore.USMANFAIAQ. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check the following Trend Micro Support pages for more information:


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