TROJ_COSSTA.SZV


 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

1,024,000 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

05 Sep 2014

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.

Installation

This Trojan creates the following folders:

  • %System Root%\config
  • %System Root%\config\ref
  • %User Temp%\temp_log
  • %User Temp%\temp_log\chat
  • %User Temp%\temp_log\tmp
  • %User Temp%\plugins
  • %User Temp%\pls
  • %User Temp%\goo
  • %User Temp%\sss3cc5ec883ec
  • %User Profile%\pzr6202a8682bc0
  • %User Temp%\pzr6202a8682bc0
  • %User Profile%\pzr6202a8682bc0\config
  • %User Profile%\config\ref
  • %User Temp%\pzr6202a8682bc0\temp_log
  • %User Temp%\pzr6202a8682bc0\temp_log\chat
  • %User Temp%\pzr6202a8682bc0\temp_log\tmp
  • %User Temp%\pzr6202a8682bc0\plugins
  • %User Temp%\pzr6202a8682bc0\pls
  • %User Temp%\pzr6202a8682bc0\goo

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Other System Modifications

This Trojan deletes the following files:

  • %System Root%\strings.txt
  • %System Root%\AUTOEXEC.BAT
  • %System Root%\config\tm.t
  • %System Root%\config\script.txt
  • %System Root%\config\update.txt
  • %System Root%\config\configure
  • %System Root%\config\notor
  • %System Root%\config\name.drv
  • %System Root%\config\exitd.vxd
  • %System Root%\CONFIG.SYS
  • %User Temp%\58e0ef.mst
  • %User Temp%\AdobeARM.log
  • %User Temp%\AdobeSFX.log
  • %User Temp%\ASPNETSetup_00000.log
  • %User Temp%\ASPNETSetup_00001.log
  • %User Temp%\ASPNETSetup_00002.log
  • %User Temp%\dd_depcheck_NETFX_EXP_35.txt
  • %User Temp%\dd_dotnetfx35error.txt
  • %User Temp%\dd_dotnetfx35install.txt
  • %User Temp%\dd_dotNetFx40_Full_x86_x64_decompression_log.txt
  • %User Temp%\dd_MSXML6_MSI0686.txt
  • %User Temp%\dd_netfx20MSI7F16.txt
  • %User Temp%\dd_netfx20UI7F16.txt
  • %User Temp%\dd_NET_Framework20_Setup06A7.txt
  • %User Temp%\dd_NET_Framework30_Setup0775.txt
  • %User Temp%\dd_NET_Framework35_MSI07B9.txt
  • %User Temp%\dd_RGB9RAST_x86.msi0683.txt
  • %User Temp%\dd_vcredistMSI3CAA.txt
  • %User Temp%\dd_vcredistMSI7C21.txt
  • %User Temp%\dd_vcredistUI3CAA.txt
  • %User Temp%\dd_vcredistUI7C21.txt
  • %User Temp%\dd_wcf_CA_smci_20111017_044900_062.txt
  • %User Temp%\dd_wcf_retCA29BA.txt
  • %User Temp%\dd_WIC.txt
  • %User Temp%\dd_XPS.txt
  • %User Temp%\Microsoft .NET Framework 4 Setup_20111016_234618578-MSI_netfx_Core_x86.msi.txt
  • %User Temp%\Microsoft .NET Framework 4 Setup_20111016_234618578-MSI_netfx_Extended_x86.msi.txt
  • %User Temp%\Microsoft .NET Framework 4 Setup_20111016_234618578.html
  • %User Temp%\Microsoft Visual C++ 2010 x86 Redistributable Setup_20111020_000954642-MSI_vc_red.msi.txt
  • %User Temp%\Microsoft Visual C++ 2010 x86 Redistributable Setup_20111020_000954642.html
  • %User Temp%\tproc.1
  • %User Temp%\tproc.2
  • %User Temp%\usb.exit
  • %User Temp%\uxeventlog.txt
  • %User Temp%\vminst.log_20111016_212239_Failed.log
  • %User Temp%\vminst.log_20130313_012028.log
  • %User Temp%\vminst.log_20130313_012352_Failed.log
  • %User Temp%\vmmsi.log_20111016_212246_Failed.log
  • %User Temp%\vmmsi.log_20130313_012028.log
  • %User Temp%\vmmsi.log_20130313_012352_Failed.log
  • %User Temp%\WSFF8.tmp
  • %User Temp%\WSFF9.tmp

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

It deletes the following folders:

  • %User Temp%\Microsoft .NET Framework 4 Setup_4.0.30319
  • %User Temp%\Microsoft Visual C++ 2010 x86 Redistributable Setup_10.0.30319
  • %User Temp%\{835818DD-220C-4ABD-946E-0D8660B95E29}

(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, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Dropping Routine

This Trojan drops the following files:

  • %User Startup%\{malware file name}.lnk
  • %User Profile%\config\notor
  • %User Profile%\config\script.txt
  • %User Profile%\config\update.txt
  • %User Profile%\config\configure
  • %User Profile%\config\name.drv
  • %User Profile%\config\exitd.vxd

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://dasan.{BLOCKED}g.ac.kr/~appmath/test/bbs/strings.txt
  • http://www.{BLOCKED}e.com.br
  • http://www.{BLOCKED}o.com
  • http://www.{BLOCKED}n.com
  • http://www.{BLOCKED}a.com.br
  • http://www.{BLOCKED}ess.com
  • http://www.{BLOCKED}hanin.org/bbs/include/eu.txt
  • http://www.{BLOCKED}ysolutions.com/.../IRPF2008/rwk.txt
  • http://www.{BLOCKED}lm.com.ua/forum/files/.../rwk.txt
  • {BLOCKED}7.239.150
  • {BLOCKED}0.1
  • {BLOCKED}.228.23
  • {BLOCKED}.180.149
  • {BLOCKED}2.82.163
  • {BLOCKED}169.244
  • {BLOCKED}.123.234
  • {BLOCKED}.250.153
  • {BLOCKED}.4.62

It deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.700

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

Search and delete these components

[ Learn More ]
There may be some components 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 Startup%\{malware file name}.lnk
  • %User Profile%\config\notor
  • %User Profile%\config\script.txt
  • %User Profile%\config\update.txt
  • %User Profile%\config\configure
  • %User Profile%\config\name.drv
  • %User Profile%\config\exitd.vxd

Step 3

Search and delete these folders

[ 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.
  • %System Root%\config
  • %System Root%\config\ref
  • %User Temp%\temp_log
  • %User Temp%\temp_log\chat
  • %User Temp%\temp_log\tmp
  • %User Temp%\plugins
  • %User Temp%\pls
  • %User Temp%\goo
  • %User Temp%\sss3cc5ec883ec
  • %User Profile%\pzr6202a8682bc0
  • %User Temp%\pzr6202a8682bc0
  • %User Profile%\pzr6202a8682bc0\config
  • %User Profile%\config\ref
  • %User Temp%\pzr6202a8682bc0\temp_log
  • %User Temp%\pzr6202a8682bc0\temp_log\chat
  • %User Temp%\pzr6202a8682bc0\temp_log\tmp
  • %User Temp%\pzr6202a8682bc0\plugins
  • %User Temp%\pzr6202a8682bc0\pls
  • %User Temp%\pzr6202a8682bc0\goo

Step 4

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

Step 5

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %System Root%\strings.txt
  • %System Root%\AUTOEXEC.BAT
  • %System Root%\config\tm.t
  • %System Root%\config\script.txt
  • %System Root%\config\update.txt
  • %System Root%\config\configure
  • %System Root%\config\notor
  • %System Root%\config\name.drv
  • %System Root%\config\exitd.vxd
  • %System Root%\CONFIG.SYS
  • %User Temp%\58e0ef.mst
  • %User Temp%\AdobeARM.log
  • %User Temp%\AdobeSFX.log
  • %User Temp%\ASPNETSetup_00000.log
  • %User Temp%\ASPNETSetup_00001.log
  • %User Temp%\ASPNETSetup_00002.log
  • %User Temp%\dd_depcheck_NETFX_EXP_35.txt
  • %User Temp%\dd_dotnetfx35error.txt
  • %User Temp%\dd_dotnetfx35install.txt
  • %User Temp%\dd_dotNetFx40_Full_x86_x64_decompression_log.txt
  • %User Temp%\dd_MSXML6_MSI0686.txt
  • %User Temp%\dd_netfx20MSI7F16.txt
  • %User Temp%\dd_netfx20UI7F16.txt
  • %User Temp%\dd_NET_Framework20_Setup06A7.txt
  • %User Temp%\dd_NET_Framework30_Setup0775.txt
  • %User Temp%\dd_NET_Framework35_MSI07B9.txt
  • %User Temp%\dd_RGB9RAST_x86.msi0683.txt
  • %User Temp%\dd_vcredistMSI3CAA.txt
  • %User Temp%\dd_vcredistMSI7C21.txt
  • %User Temp%\dd_vcredistUI3CAA.txt
  • %User Temp%\dd_vcredistUI7C21.txt
  • %User Temp%\dd_wcf_CA_smci_20111017_044900_062.txt
  • %User Temp%\dd_wcf_retCA29BA.txt
  • %User Temp%\dd_WIC.txt
  • %User Temp%\dd_XPS.txt
  • %User Temp%\Microsoft .NET Framework 4 Setup_20111016_234618578-MSI_netfx_Core_x86.msi.txt
  • %User Temp%\Microsoft .NET Framework 4 Setup_20111016_234618578-MSI_netfx_Extended_x86.msi.txt
  • %User Temp%\Microsoft .NET Framework 4 Setup_20111016_234618578.html
  • %User Temp%\Microsoft Visual C++ 2010 x86 Redistributable Setup_20111020_000954642-MSI_vc_red.msi.txt
  • %User Temp%\Microsoft Visual C++ 2010 x86 Redistributable Setup_20111020_000954642.html
  • %User Temp%\tproc.1
  • %User Temp%\tproc.2
  • %User Temp%\usb.exit
  • %User Temp%\uxeventlog.txt
  • %User Temp%\vminst.log_20111016_212239_Failed.log
  • %User Temp%\vminst.log_20130313_012028.log
  • %User Temp%\vminst.log_20130313_012352_Failed.log
  • %User Temp%\vmmsi.log_20111016_212246_Failed.log
  • %User Temp%\vmmsi.log_20130313_012028.log
  • %User Temp%\vmmsi.log_20130313_012352_Failed.log
  • %User Temp%\WSFF8.tmp
  • %User Temp%\WSFF9.tmp


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