TROJ_RENOS.SML

July 25, 2013
 ALIASES:

TrojanDownloader:Win32/Renos.EK (Microsoft); Downloader-BKM (McAfee); Trojan.FakeAV.B (Symantec); PAK:UPX, Trojan.Win32.FraudPack.gtv (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan.Generic.1002686 (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 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:

77,828 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

09 Apr 2012

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_LOCAL_MACHINE\SOFTWARE\Mozilla\
MSFox

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\
MSFox
Str5 = "x6tVEq8nGbTmPkNQIrNNQAuuDXWX"

HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\
MSFox
Str9 = "zbZdFr5/CbjyPkNQIrNNQAuuDXWXEvOyhwYIMvYIWoHwgiUTaU8JbxpO"

HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\
MSFox
Str6 = "gKFdEw=="

HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\
MSFox
Str7 = "ga9ZFK1vCPLtfEhWbqZFVA=="

HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\
MSFox
Str8 = "lg=="

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
RFC1156Agent\CurrentVersion\Parameters
TrapPollTimeMilliSecs = "3a98"

(Note: The default value data of the said registry entry is 3a98.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}big-library.com/img/config.gif
  • http://{BLOCKED}big-library.com/images/box01.gif
  • http://{BLOCKED}gecatalogue.com/images/transpix.gif
  • http://{BLOCKED}5.180.145/images/box04.gif

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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_LOCAL_MACHINE\SOFTWARE\Mozilla
    • MSFox

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\Mozilla\MSFox
    • Str5 = "x6tVEq8nGbTmPkNQIrNNQAuuDXWX"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\MSFox
    • Str9 = "zbZdFr5/CbjyPkNQIrNNQAuuDXWXEvOyhwYIMvYIWoHwgiUTaU8JbxpO"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\MSFox
    • Str6 = "gKFdEw=="
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\MSFox
    • Str7 = "ga9ZFK1vCPLtfEhWbqZFVA=="
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\MSFox
    • Str8 = "lg=="

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\SOFTWARE\Microsoft\RFC1156Agent\CurrentVersion\Parameters
    • From: TrapPollTimeMilliSecs = "3a98"
      To: TrapPollTimeMilliSecs = ""3a98""

Step 5

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