W32/Sobig-F - Halflife correlation ???

Sat Aug 23 00:50:30 UTC 2003

I've scanned my Netflow logs for activity associated with the 20
machines that SoBig was targeting and I found some very curious
activity.

I routed traffic to these 20 ips to Null0.

At 3:09 I started getting traffic from 10 of the 20 machines to a
Halflife server on my network. This continued until 6:14pm.

The conversations could not be productive because of my Null route, but
what were these machines trying to do? Even more interesting is the fact
that these machines were supposed to be shutdown before 3:00. How could
they be sending data to this halflife server? I suspect that the
addresses are spoofed, but to what end?

Are there any halflife vunerabilies that the virus writers are using? It
just seems like too much of a coincidence that 10 out of 20 machines
were hitting this server.

I have the original Netflow data and the complete logs. Below is a
sample of what I was seeing. Port 27015 is the normal Halflife port.

Anyone have any ideas? or seeing anything similar?

Read: Date,Time,SrcIP,SrcPort,DstIP,DstPort,Protocol,Packets,Bytes

2003/08/22 15:09:54 67.73.21.6.50416 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:10:00 12.232.104.221.64550 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:10:03 61.38.187.59.43445 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:10:07 67.9.241.67.17414 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:10:09 63.250.82.87.2956 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:10:12 24.197.143.132.18637 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:10:23 61.38.187.59.64072 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:10:31 67.73.21.6.27900 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:10:39 65.177.240.194.1448 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:10:46 63.250.82.87.33876 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:11:16 65.177.240.194.40713 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:11:18 61.38.187.59.58060 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:11:25 24.197.143.132.4336 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 15:11:40 67.9.241.67.6812 -> XXX.XXX.XXX.XXX.27015 17 1 37
[...]
2003/08/22 18:13:27 65.95.193.138.11565 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 18:13:31 12.232.104.221.32662 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 18:13:35 61.38.187.59.28106 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 18:13:37 24.33.66.38.19736 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 18:13:38 67.9.241.67.51452 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 18:13:46 65.95.193.138.46930 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 18:13:53 61.38.187.59.16641 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 18:13:59 63.250.82.87.56358 -> XXX.XXX.XXX.XXX.27015 17 1 37
2003/08/22 18:14:09 12.232.104.221.19923 -> XXX.XXX.XXX.XXX.27015 17 1 37

Total = 1751 flows from 15:09:54 to 18:14:09

Servers hitting the Halflife machine
------------------------------------
12.232.104.221
24.33.66.38
24.197.143.132
24.202.91.43
61.38.187.59
63.250.82.87
65.95.193.138
65.177.240.194
67.9.241.67
67.73.21.6

__________________________ http://www.invision.net/ _______________________

 Matthew E. Martini, PE        InVision.com, Inc.   (631) 543-1000 x104
 Chief Technology Officer      matt at invision.net    (631) 864-8896 Fax
_______________________________________________________________________pgp_