FBI agent Marcus C. Thomas (who is mentioned in the EPIC FOIA documents) made a very interesting presentation at NANOG 20 yesterday morning, discussing Carnivore. (2000)

Agent Thomas gave a demonstration of both Carnivore 1.34 (the currently
deployed version) and Carnivore 2.0 (the development version) as well as
some of the other DragonWare tools.

Most of this information isn’t new, but it demonstrates that the
DragonWare tools can be used to massively analyze all network traffic
accessible to a Carnivore box.

The configuration screen of Carnivore shows that protocol information can
be captured in 3 different modes: Full, Pen, and None. There are check
boxes for TCP, UDP, and ICMP.

Carnivore can be used to capture all data sent to or from a given IP
address, or range of IP addresses.

It can be used to search on information in the traffic, doing matching
against text entered in the “Data Text Strings” box. This, the agent
assured us, was so that web mail could be identified and captured, but
other browsing could be excluded.

It can be used to automatically capture telnet, pop3, and FTP logins with
the click of a check box.

It can monitor mail to and/or from specific email addresses.

It can be configured to monitor based on IP address, RADIUS username, MAC
address, or network adaptor.

IPs can be manually added to a running Carnivore session for monitoring.

Carnivore allows for monitoring of specific TCP or UDP ports and port
ranges (with drop down boxes for the most common protocols).

Carnivore 2.0 is much the same, but the configuration menu is cleaner, and
it allows Boolean statements for exclusion filter creation.

The Packeteer program takes raw network traffic dumps, reconstructs the
packets, and writes them to browsable files.

CoolMiner is the post-processor session browser. The demo was version
1.2SP4. CoolMiner has the ability to replay a victim’s steps while web
browsing, chatting on ICQ, Yahoo Messenger, AIM, IRC. It can step through
telnet sessions, AOL account usage, and Netmeeting. It can display
information sent to a network printer. It can process netbios data.

CoolMiner displays summary usage, broken down by origination and
destination IP addresses, which can be selectively viewed.

Carnivore usually runs on Windows NT Workstation, but could run on Windows

Some choice quotes from Agent Thomas:

“Non-relevant data is sealed from disclosure.”

“Carnivore has no active interaction with any devices on the network.”

“In most cases Carnivore is only used with a Title III. The FBI will
deploy Carnivore without a warrant in cases where the victim is willing to
allow a Carnivore box to monitor his communication.”

“We rely on the ISP’s security [for the security of the Carnivore box].”

“We aren’t concerned about the ISP’s security.”

When asked how Carnivore boxes were protected from attack, he said that
the only way they were accessible was through dialup or ISDN. “We could
take measures all the way up to encryption if we thought it was

While it doesn’t appear that Carnivore uses a dial-back system to prevent
unauthorized access, Thomas mentioned that the FBI sometimes “uses a

firmware device to prevent unauthorized calls.”

When asked to address the concerns that FBI agents could modify Carnivore
data to plant evidence, Thomas reported that Carnivore logs FBI agents’
access attempts. The FBI agent access logs for the Carnivore box become
part of the court records. When asked the question “It’s often common
practice to write back doors into [software programs]. How do we know you
aren’t doing that?”, Thomas replied “I agree 100%. You’re absolutely

When asked why the FBI would not release source, he said: “We don’t sell
guns, even though we have them.”

When asked: “What do you do in cases where the subject is using
encryption?” Thomas replied, “This suite of devices can’t handle that.” I
guess they hand it off to the NSA.

He further stated that about 10% of the FBI’s Carnivore cases are thwarted
by the use of encryption, and that it is “more common to find encryption
when we seize static data, such as on hard drives.”

80% of Carnivore cases have involved national security.

Marcus Thomas can be contacted for questions at mthomas@fbi.gov or at
(730) 632-6091. He is “usually at his desk.”

24 October 2000

Find this story at 24 October 2000