PUA_DLOAD


 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


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

  TECHNICAL DETAILS

File Size:

677,096 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

07 Jan 2016

Arrival Details

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

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CLASSES_ROOT\daffodil.fulgid.1

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
daffodil.fulgid.1\CLSID

HKEY_CLASSES_ROOT\daffodil.fulgid

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
daffodil.fulgid\CurVer

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}\ProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}\VersionIndependentProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}\Programmable

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}\LocalServer32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}\TypeLib

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}\Version

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A45DC262-19B3-4AE8-9AB9-EBC07454EABB}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A45DC262-19B3-4AE8-9AB9-EBC07454EABB}\1.0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A45DC262-19B3-4AE8-9AB9-EBC07454EABB}\1.0\
FLAGS

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A45DC262-19B3-4AE8-9AB9-EBC07454EABB}\1.0\
0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A45DC262-19B3-4AE8-9AB9-EBC07454EABB}\1.0\
0\win32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A45DC262-19B3-4AE8-9AB9-EBC07454EABB}\1.0\
HELPDIR

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{93A620FD-92BC-427C-B29B-465A1C676637}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{93A620FD-92BC-427C-B29B-465A1C676637}\ProxyStubClsid

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{93A620FD-92BC-427C-B29B-465A1C676637}\ProxyStubClsid32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{93A620FD-92BC-427C-B29B-465A1C676637}\TypeLib

hkey_local_machine\software\microsoft\
esent\process\{malware file name}

hkey_local_machine\software\microsoft\
esent\process\{malware file name}\
debug

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}\LocalServer32
ServerExecutable = "{malware path and file name}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{93A620FD-92BC-427C-B29B-465A1C676637}\TypeLib
Version = "1.0"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
EventMessageFile = "%System%\ESENT.dll"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
CategoryMessageFile = "%System%\ESENT.dll"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
CategoryCount = "1"

(Note: The default value data of the said registry entry is 10.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
TypesSupported = "7"

(Note: The default value data of the said registry entry is 7.)

Dropping Routine

This Trojan drops the following files:

  • {malware path and file name}:typelib

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}0.1
  • {BLOCKED}25.106

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.8

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

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_CLASSES_ROOT
    • daffodil.fulgid.1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\daffodil.fulgid.1
    • CLSID
  • In HKEY_CLASSES_ROOT
    • daffodil.fulgid
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\daffodil.fulgid
    • CurVer
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
    • {6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}
    • ProgID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}
    • VersionIndependentProgID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}
    • Programmable
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}
    • LocalServer32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}
    • TypeLib
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}
    • Version
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib
    • {A45DC262-19B3-4AE8-9AB9-EBC07454EABB}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A45DC262-19B3-4AE8-9AB9-EBC07454EABB}
    • 1.0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A45DC262-19B3-4AE8-9AB9-EBC07454EABB}\1.0
    • FLAGS
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A45DC262-19B3-4AE8-9AB9-EBC07454EABB}\1.0
    • 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A45DC262-19B3-4AE8-9AB9-EBC07454EABB}\1.0\0
    • win32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A45DC262-19B3-4AE8-9AB9-EBC07454EABB}\1.0
    • HELPDIR
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface
    • {93A620FD-92BC-427C-B29B-465A1C676637}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{93A620FD-92BC-427C-B29B-465A1C676637}
    • ProxyStubClsid
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{93A620FD-92BC-427C-B29B-465A1C676637}
    • ProxyStubClsid32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{93A620FD-92BC-427C-B29B-465A1C676637}
    • TypeLib
  • In hkey_local_machine\software\microsoft\esent\process
    • {malware file name}
  • In hkey_local_machine\software\microsoft\esent\process\{malware file name}
    • debug

Step 3

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_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{6e357dfb-9f9d-40a3-95d3-ef0f44031ab2}\LocalServer32
    • ServerExecutable = "{malware path and file name}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{93A620FD-92BC-427C-B29B-465A1C676637}\TypeLib
    • Version = "1.0"

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
    • From: EventMessageFile = "%System%\ESENT.dll"
      To: EventMessageFile = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
    • From: CategoryMessageFile = "%System%\ESENT.dll"
      To: CategoryMessageFile = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
    • From: CategoryCount = "1"
      To: CategoryCount = ""10""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
    • From: TypesSupported = "7"
      To: TypesSupported = ""7""

Step 5

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.
  • {malware path and file name}:typelib

Step 6

Scan your computer with your Trend Micro product to delete files detected as PUA_DLOAD. 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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