Analysis by: Janus Agcaoili
ALIASES:

Trojan.Zelocat (Symantec), Riskware/ZhCat (Fortinet), Tool.ZhCat.1 (DrWeb)

 PLATFORM:

Windows

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

  • Threat Type: Hacking Tool

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

This hacking tool 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: 12800 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 13 May 2014

Arrival Details

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

Other Details

This hacking tool does the following:

  • Should be executed in command line window with parameters in order to run properly
  • It accepts the following parameters as arguments:
    • -l or --listen <- turns into server mode
    • -h or --http <- perform http flood
    • -x or --xor <- encrypt network traffic
    • -e or --executable <- run executable after connecting
    • -i or --ip <- listen to specific IP (no ip = all ip)
    • -p or --port <- listen to specific port
    • -ti or --tunnel-ip <- tunnel IP(get into tunnel mode)
    • -tp or --tunnel-port <- tunnel port(get into tunnel mode)
    • -ri or --redir-ip <- redirect IP(get into redirecting mode)
    • -rp or --redir-port <- redirect port(get into redirecting mode)
    • -d or --dump <- dump traffic into file (recvDump & sendDump)
    • -? or --help <- print help
  • Names the dump files as:
    • {Current Directory}\sendDumpS.log
    • {Current Directory}\sendDumpC.log
    • {Current Directory}\recvDumpS.log
    • {Current Directory}\recvDumpC.log
  • Capable of logging its backdoor activities by executing the file, BackDoorLogger.exe - also detected as HKTL_ZHCAT.GA
  • The BackDoorLogger.exe accepts the following parameters:
    • -e - determines the zhcat executable's name
    • -d - determines the log interval in milliseconds
  • Displays the following when executed in a command line window:

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 1.684.10
FIRST VSAPI PATTERN DATE: 03 Dec 2015
VSAPI OPR PATTERN File: 1.685.00
VSAPI OPR PATTERN Date: 04 Dec 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

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.  
  • {Current Directory}\sendDumpS.log
  • {Current Directory}\sendDumpC.log
  • {Current Directory}\recvDumpS.log
  • {Current Directory}\recvDumpC.log

Step 4

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