possible intruder alert

Posted on 2003-12-11
Last Modified: 2010-04-11
I have my cisco set up and my router keeps denying a call on port 135. Can anyone tell me what this is or help me research this.

Thanks, Troy
Question by:troyd1
LVL 19

Accepted Solution

Dexstar earned 25 total points
ID: 9925045

> Can anyone tell me what this is or help me research this.

Port 135 is used by Microsoft for RPC.  Read all about it:

Hope That Helps,
LVL 18

Assisted Solution

chicagoan earned 25 total points
ID: 9925525
LVL 79

Expert Comment

ID: 9928046
A router can only deny what it is told to. Do you have any access-lists?
Perhaps the ISP is blocking tcp 135 further upstream. This is a recent phenomenon since the outbreak of MSBlast and Welchia worms.

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Expert Comment

ID: 9928693
Sounds like Welchia or Blaster or one of the other RPC exploiters are knocking.  Luckily, you have a firewall.  I recommend you leave 135 blocked.  And find out the source of the requests (there should be an associated IP Address).  Report this IP address to your ISP and ask them to investigate it, as the source Host may be infected with a Virus/Worm.

And remember, the triad of virus protection:
1. Firewall
2. Up To Date Antivirus Software
3. Latest Operating System patches and fixes whether they be MS, *nix, or Mac
LVL 18

Expert Comment

ID: 9928854
If it ticks you off that you're being probed, take a look at
There some good info about security there as well.

Expert Comment

ID: 9928895
oh, and listen to Irmoore.  If you take a look to the right, at that list of the Top 15 Experts...

Author Comment

ID: 9930057
Thanks for all the info. This was all good info.

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