Strange Client Behavior: Port 8002 Looking for Other Ports

W

Will

I have strange symptoms on a Windows 2000 client. For long
periods each day, this client, which is behind Microsoft Proxy
2.0, stops access to the Internet. In the sniffer trace, what
I see is repetitive behavior where the client will send out TCP
connections from source port 8002 to successive ports on our DNS
server. It appears to attempt connection to each port three
times, and then it goes on to the next one. 1937, 1938, 1939,
etc.

This sure looks like some kind of port sniffing activity, maybe a
virus, but does anyone recognize the source port number and
behavior as belonging to some legitimate Windows 2000 client
behavior?
 
S

Shalom B.

I would first try and use the following command to list all network
connections and the PID of each process involved in the connections
listed and then use the Windows Task Manager to find the Image Name of
the Process with the corresponding PID.

% Netstat.exe -ano

Below is a utility I wrote, a simple batch file that enhances
Netstat.exe and includes the Process's Image Name in the output, It
however requires Tasklist.exe which unfortunately is not found on
Windows 2000 but if you manage to get your hands on Tasklist.exe from an
XP installation, it should work fine.

:: BEGIN Netstate.cmd

@echo off
setlocal

if "%1"=="" set param=-an

set sys32=%windir%\system32
%sys32%\ipconfig.exe | find /i "ip address" > %temp%\IPCFG && for /f
"tokens=15 delims= " %%g in (%temp%\IPCFG) do (
set IP_ADD=%%g
)

for /f %%g in ('%sys32%\hostname.exe') do set Hostname=%%g

%sys32%\netstat.exe -p TCP -o %param% | find /i /v "Foreign Address" |
find /i /v "Active Connections" >> %temp%\TCPS
%sys32%\netstat.exe -p UDP -o %param% | find /i /v "Foreign Address" |
find /i /v "Active Connections" >> %temp%\UDPS


for /f "tokens=1,2,3,4,5,6,7 delims=: " %%g in (%temp%\TCPS) do (

for /f "tokens=1,2 delims= " %%y in (

'%sys32%\tasklist.exe /NH /FI "PID eq %%m"'

) do (

echo. %%g, %%h%IADDR_LOCAL%, %%i, %%j%IADDR_REMOTE%, %%k, %%l, %%y, %%z
)

)


for /f "tokens=1,2,3,4,5,6 delims=: " %%g in (
%temp%\UDPS
) do (
for /f "tokens=1,2 delims= " %%y in ('%sys32%\tasklist.exe /NH /FI
"PID eq %%l"') do (
echo. %%g, %%h, %%i, %%j, %%k, , %%y, %%z
)
)

endlocal

del /f %temp%\TCPS
del /f %temp%\UDPS
del /f %temp%\IPCFG

:: END Netstate.cmd
I have strange symptoms on a Windows 2000 client. For long
periods each day, this client, which is behind Microsoft Proxy
2.0, stops access to the Internet. In the sniffer trace, what
I see is repetitive behavior where the client will send out TCP
connections from source port 8002 to successive ports on our DNS
server. It appears to attempt connection to each port three
times, and then it goes on to the next one. 1937, 1938, 1939,
etc.

This sure looks like some kind of port sniffing activity, maybe a
virus, but does anyone recognize the source port number and
behavior as belonging to some legitimate Windows 2000 client
behavior?

@echo off
setlocal

if "%1"=="" set param=-an

:: Variable Initilisations
set sys32=%windir%\system32
%sys32%\ipconfig.exe | find /i "ip address" > %temp%\IPCFG && for /f "tokens=15 delims= " %%g in (%temp%\IPCFG) do (
set IP_ADD=%%g
)

for /f %%g in ('%sys32%\hostname.exe') do set Hostname=%%g

%sys32%\netstat.exe -p TCP -o %param% | find /i /v "Foreign Address" | find /i /v "Active Connections" >> %temp%\TCPS
%sys32%\netstat.exe -p UDP -o %param% | find /i /v "Foreign Address" | find /i /v "Active Connections" >> %temp%\UDPS


for /f "tokens=1,2,3,4,5,6,7 delims=: " %%g in (%temp%\TCPS) do (

for /f "tokens=1,2 delims= " %%y in (

'%sys32%\tasklist.exe /NH /FI "PID eq %%m"'

) do (

echo. %%g, %%h%IADDR_LOCAL%, %%i, %%j%IADDR_REMOTE%, %%k, %%l, %%y, %%z
)

)


for /f "tokens=1,2,3,4,5,6 delims=: " %%g in (
%temp%\UDPS
) do (
for /f "tokens=1,2 delims= " %%y in ('%sys32%\tasklist.exe /NH /FI "PID eq %%l"') do (
echo. %%g, %%h, %%i, %%j, %%k, , %%y, %%z
)
)

endlocal

del /f %temp%\TCPS
del /f %temp%\UDPS
del /f %temp%\IPCFG
 

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