Analysis by: Pearl Charlaine Espejo
ALIASES:

W32.HfsAdware.6E7F (Bkav); Riskware/Systweak (Fortinet); PUP.RiskWare.Systweak (Malwarebytes)

 PLATFORM:

Windows

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

  • Threat Type: Potentially Unwanted Application

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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 may be manually installed by a user.

  TECHNICAL DETAILS

File Size: 10,537,520 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 23 Sep 2015

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.

It may be manually installed by a user.

Installation

This potentially unwanted application adds the following folders:

  • %Program Files%\Dll-Files.com Fixer
  • %All Users Profile%\Start Menu\Programs\Dll-Files Fixer
  • %Application Data%\dll-files.com
  • %Application Data%\dll-files.com\Fixer
  • %Application Data%\dll-files.com\Fixer\Version 1.0
  • %User Temp%\is-{random characters}.tmp
  • %User Temp%\is-{random characters}.tmp\_isetup

It drops the following files:

  • %User Temp%\is-{random characters}.tmp\dffsetup.tmp
  • %User Temp%\is-{random characters}.tmp\_isetup\_shfoldr.dll
  • %Program Files%\Dll-Files.com Fixer\is-{random characters}.tmp
  • %Program Files%\Dll-Files.com Fixer\Chinese_rcp.ini
  • %Program Files%\Dll-Files.com Fixer\CleanSchedule.exe
  • %Program Files%\Dll-Files.com Fixer\DLLFixer.exe
  • %Program Files%\Dll-Files.com Fixer\Danish_rcp.ini
  • %Program Files%\Dll-Files.com Fixer\Dutch_rcp.ini
  • %Program Files%\Dll-Files.com Fixer\Finnish_rcp_fi.ini
  • %Program Files%\Dll-Files.com Fixer\French_rcp.ini
  • %Program Files%\Dll-Files.com Fixer\German_rcp.ini
  • %Program Files%\Dll-Files.com Fixer\Italian_rcp.ini
  • %Program Files%\Dll-Files.com Fixer\Japanese_rcp.ini
  • %Program Files%\Dll-Files.com Fixer\Norwegian_rcp.ini
  • %Program Files%\Dll-Files.com Fixer\Portuguese_rcp.ini
  • %Program Files%\Dll-Files.com Fixer\RegCleanPro.dll
  • %Program Files%\Dll-Files.com Fixer\Spanish_rcp.ini
  • %Program Files%\Dll-Files.com Fixer\Swedish_rcp.ini
  • %Program Files%\Dll-Files.com Fixer\TraditionalCn_rcp_zh-tw.ini
  • %Program Files%\Dll-Files.com Fixer\eng_rcp.ini
  • %Program Files%\Dll-Files.com Fixer\greek_rcp_el.ini
  • %Program Files%\Dll-Files.com Fixer\install_left_image.bmp
  • %Program Files%\Dll-Files.com Fixer\isxdl.dll
  • %Program Files%\Dll-Files.com Fixer\korean_rcp_ko.ini
  • %Program Files%\Dll-Files.com Fixer\polish_rcp_pl.ini
  • %Program Files%\Dll-Files.com Fixer\portugese_rcp_pt.ini
  • %Program Files%\Dll-Files.com Fixer\russian_rcp_ru.ini
  • %Program Files%\Dll-Files.com Fixer\turkish_rcp_tr.ini
  • %Program Files%\Dll-Files.com Fixer\unins000.dat
  • %Program Files%\Dll-Files.com Fixer\unins000.exe
  • %Program Files%\Dll-Files.com Fixer\unins000.msg
  • %Program Files%\Dll-Files.com Fixer\xmllite.dll
  • %Desktop%\Dll-Files Fixer.lnk
  • %All Users Profile%\Start Menu\Programs\Dll-Files Fixer\Dll-Files Fixer.lnk
  • %All Users Profile%\Start Menu\Programs\Dll-Files Fixer\Uninstall Dll-Files Fixer.lnk
  • %Application Data%\Microsoft\Internet Explorer\Quick Launch\Dll-Files Fixer.lnk
  • %Application Data%\dll-files.com\Fixer\Version 1.0\log_{system date}.log
  • %Application Data%\dll-files.com\Fixer\Version 1.0\results.rcp
  • %Application Data%\Logs\{random filename}.license.log
  • %Windows%\Tasks\DLL-Files.Com Fixer_MONTHLY.job
  • %Windows%\Tasks\DLL-Files.Com Fixer_Updates.job

Autostart Technique

This potentially unwanted application adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
RDReminder = "%Program Files%\Dll-Files.com Fixer\DLLFixer.exe -rem"

Other System Modifications

This potentially unwanted application adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1

HKEY_LOCAL_MACHINE\SOFTWARE\dll-files.com

HKEY_LOCAL_MACHINE\SOFTWARE\dll-files.com\
Fixer

HKEY_LOCAL_MACHINE\SOFTWARE\dll-files.com\
Fixer\Version 1.0

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0\LANG

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
Inno Setup: Setup Version = "{version number} (u)"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
Inno Setup: App Path = "%Program Files%\Dll-Files.com Fixer"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
InstallLocation = "%Program Files%\Dll-Files.com Fixer\"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
Inno Setup: Icon Group = "Dll-Files Fixer"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
Inno Setup: User = "{username}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
Inno Setup: Selected Tasks = "desktopicon,quicklaunchicon"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
Inno Setup: Deselected Tasks = ""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
Inno Setup: Language = "en"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
DisplayName = "Dll-Files Fixer"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
DisplayIcon = "%Program Files%\Dll-Files.com Fixer\DLLFixer.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
UninstallString = ""%Program Files%\Dll-Files.com Fixer\unins000.exe""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
QuietUninstallString = ""%Program Files%\Dll-Files.com Fixer\unins000.exe" /SILENT"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
DisplayVersion = "{version number}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
Publisher = "Dll-Files.com"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
URLInfoAbout = "http://www.dll-files.com/fixer/"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
HelpLink = "http://www.dll-files.com/fixer/"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
NoModify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
NoRepair = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
InstallDate = "{system date}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
MajorVersion = "3"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
MinorVersion = "2"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Dll-Files Fixer_is1
UninstallString = ""%Program Files%\Dll-Files.com Fixer\unins000.exe" /silent"

HKEY_LOCAL_MACHINE\SOFTWARE\dll-files.com\
Fixer\Version 1.0
utm_source = ""

HKEY_LOCAL_MACHINE\SOFTWARE\dll-files.com\
Fixer\Version 1.0
utm_campaign = ""

HKEY_LOCAL_MACHINE\SOFTWARE\dll-files.com\
Fixer\Version 1.0
RCPURL = "http://www.dll-files.com/get-fixer/?"

HKEY_LOCAL_MACHINE\SOFTWARE\dll-files.com\
Fixer\Version 1.0
RENEWALURL = "http://www.dll-files.com/renew-subscriptions/?"

HKEY_LOCAL_MACHINE\SOFTWARE\dll-files.com\
Fixer\Version 1.0
DLLFILENAME = ""

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0\LANG
LangCode = "en"

HKEY_LOCAL_MACHINE\SOFTWARE\dll-files.com\
Fixer\Version 1.0\LANG
LangID = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\dll-files.com\
Fixer\Version 1.0
Expired = "0"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
FirstRun = "1"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
StartAutoScanPMUI = "0"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
CurrentScanTime = "{hex value}"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
SetChkREmovableMedia = "1"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
SetChkSkipEmptyKeys = "1"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
ImprovementProgram = 1"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
StartWhenWinBoots = "1"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
GoToSystemTrayOnClose = "0"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
ConfirmBkUps = "1"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
StartScan = "0"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
StartMinimized = "0"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
AutoRepair = "0"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
StrLastScan = "{System date and time}"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
StrLastScanResults = "{numbers}"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
StrLastOptimizeTime = ""

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
StrLatestRegDefrag = ""

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
StrLatestRestorePoint = ""

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
StrLastStartupOpt = ""

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
RegErrFoundTillDate = "{numbers}"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
RegErrsFixedTillDate = "{numbers}"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
RegErrsFixedLast = "{numbers}"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
ScheduledTime = ""

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
NumTimesRCPRunned = "{numbers}"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
ChkAgreeToUploadDLLs = "1"

HKEY_CURRENT_USER\Software\dll-files.com\
Fixer\Version 1.0
StrLastScanResults = "{numbers}"

Other Details

This potentially unwanted application connects to the following possibly malicious URL:

  • http://www.{BLOCKED}les.com/
  • http://www.{BLOCKED}les.com/fixer/
  • http://www.{BLOCKED}les.com/get-fixer/?
  • http://www.{BLOCKED}les.com/renew-subscriptions/?
  • http://www.{BLOCKED}les.com/thank-you-for-installing/?type={type}&langid={language}&down_file={data}

  SOLUTION

Minimum Scan Engine: 9.750
SSAPI PATTERN File: 1.667.00
SSAPI PATTERN Date: 09 Oct 2015

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 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

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • RDReminder = "%Program Files%\Dll-Files.com Fixer\DLLFixer.exe -rem"

Step 5

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
    • Dll-Files Fixer_is1
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • dll-files.com

Step 6

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.  
  • %User Temp%\is-{random characters}.tmp
  • %Program Files%\Dll-Files.com Fixer
  • %All Users Profile%\Start Menu\Programs\Dll-Files Fixer
  • %Application Data%\dll-files.com

Step 7

Search and delete these files

[ 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.
  • %Desktop%\Dll-Files Fixer.lnk
  • %Application Data%\Microsoft\Internet Explorer\Quick Launch\Dll-Files Fixer.lnk
  • %Application Data%\Logs\{random filename}.license.log
  • %Windows%\Tasks\DLL-Files.Com Fixer_MONTHLY.job
  • %Windows%\Tasks\DLL-Files.Com Fixer_Updates.job

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as PUA_FIXFILES.GA. 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 this Knowledge Base page for more information.


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