Virus:Worm/IRCBot.NG
Date discovered:23/01/2006
Type:Worm
In the wild:No
Reported Infections:Low
Distribution Potential:Medium
Damage Potential:Medium
Static file:Yes
File size:61.952 Bytes
MD5 checksum:1dca55b49c62164fee54686861d2bda4
VDF version:6.33.00.150

 General Method of propagation:
   • Local network


Aliases:
   •  Kaspersky: Backdoor.Win32.IRCBot.ng
   •  TrendMicro: WORM_IRCBOT.DR
   •  Bitdefender: Backdoor.IRCBot.GB


Platforms / OS:
   • Windows 95
   • Windows 98
   • Windows 98 SE
   • Windows NT
   • Windows ME
   • Windows 2000
   • Windows XP
   • Windows 2003


Side effects:
   • Downloads a malicious file
   • Lowers security settings
   • Registry modification
   • Makes use of software vulnerability
   • Third party control

 Files It copies itself to the following location:
   • %SYSDIR%\auditchk.exe




It tries to download a file:

– The location is the following:
   • mildred.debelizombi.com/**********
It is saved on the local hard drive under: %TEMPDIR%\dl%eight-digit random character string%.exe Furthermore this file gets executed after it was fully downloaded. Further investigation pointed out that this file is malware, too. Detected as: TR/Dldr.Small.cgc.1

 Registry The following registry keys are added in order to run the processes after reboot:

– [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   • "Printer"="%SYSDIR%\auditchk.exe"

– [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices]
   • "Printer"="%SYSDIR%\auditchk.exe"

– [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   • "Printer"="%SYSDIR%\auditchk.exe"



The following registry keys are changed:

– [HKLM\SOFTWARE\Microsoft\Ole]
   Old value:
   • "EnableDCOM"=%user defined settings%
   New value:
   • "EnableDCOM"="N"

– [HKLM\SYSTEM\CurrentControlSet\Control\Lsa]
   Old value:
   • "restrictanonymous"= %user defined settings%
   New value:
   • "restrictanonymous"=dword:00000001

 Network Infection In order to ensure its propagation the malware attemps to connect to other machines as described below.


Exploit:
It makes use of the following Exploits:
– MS01-059 (Unchecked Buffer in Universal Plug and Play)
– MS03-026 (Buffer Overrun in RPC Interface)
– MS03-039 (Buffer Overrun in RPCSS Service)
– MS04-007 (ASN.1 Vulnerability)


Infection process:
Creates a TFTP script on the compromised machine in order to download the malware to the remote location.

 IRC To deliver system information and to provide remote control it connects to the following IRC Server:

Server: irc.debeli**********
Port: 8080
Channel: #!bla!
Nickname: [XP]|%eight-digit random character string%
Password: tn10a4



– This malware has the ability to collect and send information such as:
    • Malware uptime
    • Information about running processes


– Furthermore it has the ability to perform actions such as:
    • connect to IRC server
    • Launch DDoS ICMP flood
    • Disable DCOM
    • disconnect from IRC server
    • Download file
    • Enable DCOM
    • Execute file
    • Join IRC channel
    • Kill process
    • Leave IRC channel
    • Perform network scan
    • Start spreading routine

 Miscellaneous Mutex:
It creates the following Mutex:
   • rxRizzo_v1.1b

 File details Programming language:
 The malware program was written in MS Visual C++.


Runtime packer:
In order to aggravate detection and reduce size of the file it is packed with the following runtime packer:
   • Morphine

Description inserted by Daniel Constantin on Monday, February 6, 2006
Description updated by Daniel Constantin on Thursday, February 9, 2006

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