The backdoor's file is a Windows PE executable about 63 kilobytes long, packed with a file compressor. Some of the backdoor's strings are encrypted with a simple algorithm. The encryption key is not stored in the body of the backdoor, it is generated during runtime.
After the backdoor's file is run, it copies itself to Windows System folder and creates a startup key value for its file in Windows Registry. The backdoor can copy itself with any of the following names:
The following startup keys may be created under the following Registry keys:
Startup key values can be:
"Local Security Authority Service" = "%WinSysDir%\lssas.exe"
"Local Security Authority Service" = "%WinSysDir%\Isass.exe"
"Client Server Runtime Process" = "%WinSysDir%\csrs.exe"
"Windows Logon Application" = "%WinSysDir%\logon.exe"
"Windows Logon Application" = "%WinSysDir%\winIogon.exe"
"Windows Explorer" = "%WinSysDir%\explorer.exe"
"Winamp Agent" = "%WinSysDir%\winamp.exe"
"Windows Network Firewall" = "%WinSysDir%\firewall.exe"
"Spooler SubSystem App" = "%WinSysDir%\spoolsvc.exe"
Spooler SubSystem App" = "%WinSysDir%\spooIsv.exe"
"Application Layer Gateway Service" = "%WinSysDir%\algs.exe"
"Microsoft Internet Explorer" = "%WinSysDir%\iexplore.exe"
where %WinSysDir% represents Windows System folder. On Windows XP systems it is usually C:\Windows\System32\
After installation the backdoor connects to an IRC server and creates a bot in a specific channel. A hacker who is present in a channel can control the backdoor by sending specific commands to a bot. After installation the backdoor deletes the file that it was originally started from.
The backdoor has the following capabilities:
- joins and parts IRC channels, changes nick, creates clones, sends raw command, sends messages and notices, floods channels
- runs IDENTD server on a specified port
- scans for vulnerable computers using a number of exploits (see below) and reports to a hacker
- tries to spread to network shares, bruteforces share passwords using the hardcoded list
- steals logins and passwords (cached passwords, FlashFXP passwords, IE site passwords, MSN passwords)
- steals Outlook account information (SMTP and POP server names, logins and passwords)
- steals HTTP e-mail server logins and passwords (Hotmail)
- sniffs network traffic (packet sniffer)
- downloads and runs files on an infected computer
- opens a pipe-based remote command shell on an infected computer
- act as a proxy server on a selected port
- collects information about an infected system (software and hardware configuration)
- finds and terminates competing bots
- performs a DoS (Denial of Service) attack
- updates itself from Internet
- lists processes paying attention on processes with the specific names (games mostly)
The following exploits are used by the backdoor to spread to vulnerable computers:
ASN.1 (MS04-007), ports 80, 139, 445LSASS (MS04-011), port 445DCOM-RPC (MS04-012), port 135WKSSVC (MS03-049), ports 135, 445WEBDAV (MS03-007), port 80UPNP (MS05-039), port 445
MSSQL, port 1433
DameWare, port 6129
BackupExec, port 6101
IceCast, port 8000
SlabMail, port 110
RealServer, port 554
The following list is used to bruteforce network share passwords:
The backdoor has a stub for the Ring0 code. This code is not available in this backdoor variant, but might be added into one of the future variants.
is detected with the following F-Secure Anti-Virus updates:
Version = 2006-01-04_05
Alexey Podrezov, February 1, 2006
Alexey Podrezov, February 2, 2006