Modified by: Adrian Cofreros

ALIASES:

RDN/Downloader.a!ti (McAfee); Trojan.Asprox.B (Symantec); Trojan-Downloader.Win32.Goo.pqa (Kaspersky); Troj/Wonton-IR (Sophos); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Inject2.AWYN (AVG)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

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

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: 71,168 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 21 Oct 2014
Payload: Connects to URLs/IPs, Downloads files

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 adds the following mutexes to ensure that only one of its copies runs at any one time:

  • MD7H82HHF7EH2D73

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\SOFTWARE\NVIDIA Corporation\
Global\nvUpdSrv

It adds the following registry entries:

HKEY_CURRENT_USER\Software\NVIDIA Corporation\
Global\nvUpdSrv
value = {ininitally the installed version of malware which is "12140920"}

HKEY_CURRENT_USER\Software\NVIDIA Corporation\
Global\nvUpdSrv
GUID = {GUID}

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

  • {BLOCKED}.{BLOCKED}.180.16:32136
  • {BLOCKED}.{BLOCKED}.119.253:18625
  • {BLOCKED}.{BLOCKED}.103.78:36034
  • {BLOCKED}.{BLOCKED}.211.42:58264
  • {BLOCKED}.{BLOCKED}.9.198:29296
  • {BLOCKED}.{BLOCKED}.137.9:51340
  • {BLOCKED}.{BLOCKED}.160.220:49878
  • {BLOCKED}.{BLOCKED}.138.236:46116
  • {BLOCKED}.{BLOCKED}.116.234:35621
  • {BLOCKED}.{BLOCKED}.219.16:49976
  • {BLOCKED}.{BLOCKED}.97.247:30577
  • {BLOCKED}.{BLOCKED}.143.244:48775
  • {BLOCKED}.{BLOCKED}.186.250:16193
  • {BLOCKED}.{BLOCKED}.62.4:16660
  • {BLOCKED}.{BLOCKED}.175.20:49105
  • {BLOCKED}.{BLOCKED}.42.114:18397
  • {BLOCKED}.{BLOCKED}.72.1:19919
  • {BLOCKED}.{BLOCKED}.223.18:22740
  • {BLOCKED}.{BLOCKED}.92.3:53109
  • {BLOCKED}.{BLOCKED}.227.173:19592
  • {BLOCKED}.{BLOCKED}.72.235:49719
  • {BLOCKED}.{BLOCKED}.227.1:29071
  • {BLOCKED}.{BLOCKED}.233.149:35173
  • {BLOCKED}.{BLOCKED}.250.108:19004
  • {BLOCKED}.{BLOCKED}.192.206:41023
  • {BLOCKED}.{BLOCKED}.171.130:13586
  • {BLOCKED}.{BLOCKED}.76.42:29178
  • {BLOCKED}.{BLOCKED}.1.10:49891
  • {BLOCKED}.{BLOCKED}.4.190:19413
  • {BLOCKED}.{BLOCKED}.148.126:58046
  • {BLOCKED}.{BLOCKED}.51.32:33008
  • {BLOCKED}.{BLOCKED}.84.52:12825
  • {BLOCKED}.{BLOCKED}.82.43:51515
  • {BLOCKED}.{BLOCKED}.243.115:25603
  • {BLOCKED}.{BLOCKED}.211.203:32872
  • {BLOCKED}.{BLOCKED}.48.190:61307
  • {BLOCKED}.{BLOCKED}.145.14:37470
  • {BLOCKED}.{BLOCKED}.119.254:38354
  • {BLOCKED}.{BLOCKED}.73.170:27174
  • {BLOCKED}.{BLOCKED}.94.2:11754
  • {BLOCKED}.{BLOCKED}.11.115:15396
  • {BLOCKED}.{BLOCKED}.215.209:15551
  • {BLOCKED}.{BLOCKED}.149.150:62059
  • {BLOCKED}.{BLOCKED}.26.250:19285
  • {BLOCKED}.{BLOCKED}.155.156:30111
  • {BLOCKED}.{BLOCKED}.151.187:39179
  • {BLOCKED}.{BLOCKED}.9.199:25127
  • {BLOCKED}.{BLOCKED}.82.41:21999
  • {BLOCKED}.{BLOCKED}.58.68:23480
  • {BLOCKED}.{BLOCKED}.38.236:28654
  • {BLOCKED}.{BLOCKED}.88.50:61107
  • {BLOCKED}.{BLOCKED}.104.204:60098
  • {BLOCKED}.{BLOCKED}.153.26:51982
  • {BLOCKED}.{BLOCKED}.139.225:26545
  • {BLOCKED}.{BLOCKED}.148.25:10925
  • {BLOCKED}.{BLOCKED}.32.138:10315
  • {BLOCKED}.{BLOCKED}.126.77:33918
  • {BLOCKED}.{BLOCKED}.179.119:64167
  • {BLOCKED}.{BLOCKED}.2.42:31710
  • {BLOCKED}.{BLOCKED}.117.15:39361
  • {BLOCKED}.{BLOCKED}.145.233:54275
  • {BLOCKED}.{BLOCKED}.144.4:33816
  • {BLOCKED}.{BLOCKED}.48.52:41628
  • {BLOCKED}.{BLOCKED}.255.157:10238
  • {BLOCKED}.{BLOCKED}.250.34:33906
  • {BLOCKED}.BLOCKED}.162.167:25833
  • {BLOCKED}.{BLOCKED}.10.10:47298
  • {BLOCKED}.{BLOCKED}.248.42:36427
  • {BLOCKED}.{BLOCKED}.139.127:58914
  • {BLOCKED}.{BLOCKED}.223.12:49116
  • {BLOCKED}.{BLOCKED}.128.22:12898
  • {BLOCKED}.{BLOCKED}.205.159:51633
  • {BLOCKED}.{BLOCKED}.65.70:48741
  • {BLOCKED}.{BLOCKED}.86.17:42737
  • {BLOCKED}.{BLOCKED}.30.17:36991
  • {BLOCKED}.{BLOCKED}.36.253:35367
  • {BLOCKED}.{BLOCKED}.195.163:44937
  • {BLOCKED}.{BLOCKED}.118.200:31973
  • {BLOCKED}.{BLOCKED}.227.159:27247
  • {BLOCKED}.{BLOCKED}.96.17:16107
  • {BLOCKED}.{BLOCKED}.224.67:40259
  • {BLOCKED}.{BLOCKED}.146.9:26084
  • {BLOCKED}.{BLOCKED}.4.167:13737
  • {BLOCKED}.{BLOCKED}.113.172:48166
  • {BLOCKED}.{BLOCKED}.165.113:30007
  • {BLOCKED}.{BLOCKED}.137.179:17653
  • {BLOCKED}.{BLOCKED}.140.57:22512
  • {BLOCKED}.{BLOCKED}.197.36:31571
  • {BLOCKED}.{BLOCKED}.50.2:54663
  • {BLOCKED}.{BLOCKED}.0.237:33097
  • {BLOCKED}.{BLOCKED}.102.111:46975
  • {BLOCKED}.{BLOCKED}.43.92:41780
  • {BLOCKED}.{BLOCKED}.190.54:26630
  • {BLOCKED}.{BLOCKED}.70.40:17896
  • {BLOCKED}.{BLOCKED}.143.129:21583
  • {BLOCKED}.{BLOCKED}.126.61:60541
  • {BLOCKED}.{BLOCKED}.0.216:37288
  • {BLOCKED}.{BLOCKED}.152.141:31643
  • {BLOCKED}.{BLOCKED}.118.230:49649
  • {BLOCKED}.{BLOCKED}.107.132:19796
  • {BLOCKED}.{BLOCKED}.140.51:16549

    It saves the files it downloads using the following names:

    • %User Temp%\nvu{random}.tmp.exe - it executes this file

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

    NOTES:

    It notifies IP address mentioned above by sending the following HTTP GET request, and then waits for further acknowledgement before downloading.

    • stat?uid={value}&downlink={value}&uplink={value}&id={value}&statpass={value}&version={installed version}&features={value}&guid={guid}&comment={value}&p={value}&s={value}

    However, as of this writing this request attempts fails.

    It can also receive information on the connection and can update the value on the following registry:

    HKEY_CURRENT_USER\Software\NVIDIA Corporation\Global\nvUpdSr
    value = {value}

    It can also receive other information where it can also connect to other than the mentioned IP addresses above. It may also download into this new connections.

    It does not have rootkit capabilities.

    It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.230.05
FIRST VSAPI PATTERN DATE: 23 Aug 2015
VSAPI OPR PATTERN File: 11.231.00
VSAPI OPR PATTERN Date: 24 Aug 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 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_CURRENT_USER\SOFTWARE\NVIDIA Corporation\Global
    • nvUpdSrv

Step 5

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.  
  • %User Temp%\nvu{random}.tmp.exe

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_CARBERP.ERO. 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.


Did this description help? Tell us how we did.