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"Intrusion Signatures and Analysis", Stephen Northcutt et al, 2001, 0-7357-1063-5, U$39.99/C$59.95/UK#30.99
%A Stephen Northcutt stephen@s...
%A Mark Cooper
%A Matt Fearnow
%A Karen Frederick
%C 201 W. 103rd Street, Indianapolis, IN 46290
%D 2001
%G 0-7357-1063-5
%I Macmillan Computer Publishing (MCP)
%O U$39.99/C$59.95/UK#30.99 800-858-7674
%O http://www.amazon.com/exec/obidos/ASIN/0735710635/robsladesinterne
%O http://www.amazon.ca/exec/obidos/ASIN/0735710635/robsladesin03-20
%P 408 p.
%T "Intrusion Signatures and Analysis"

Intrusion detection and network forensics are now vitally important topics in the security arena. An explanation of how to identify dangerous signatures, and extract evidence of an intrusion or attack from network logs, is something that most network administrators require. Unfortunately, while the idea is good, and badly needed, the execution, in the case of the current work, is seriously flawed.

The introduction doesn't really specify a purpose or audience for this book. Mention is made of the GIAC (Global Incident Analysis Center, also seemingly referred to at times as the GCIA) certification, but no definition is given as to what this actually is. Chapter one presents a number of examples of network log entries and formats. The interpretation, though, concentrates on easily identifiable items such as IP addresses, and neglects components that are less well known. There seems to be some attempt to structure the descriptions, but it is unclear and confusing, as are a number of the illustrations and figures.

Chapters three and four list a "top ten" of specific attacks, described down to a byte level, but not always in clear detail. Perimeter logs, such as those from firewalls and routers, are discussed in chapter six. Restraint in reaction to odd traffic is urged in chapter seven, particularly in light of the probability of address spoofing. Chapter eight outlines packets that indicate mapping scans, while nine does the same with searches that might be gathering system information. Denial of services attacks are reviewed in chapters ten and eleven, first with respect to attacks that attempt to exhaust specific resources, and then in regard to bandwidth consumption. Chapter twelve discusses trojan programs, concentrating on detection of unusual open ports. Miscellaneous exploits are listed in chapter thirteen, but since exploits are listed throughout the previous three chapters it is difficult to find a distinctive for this section. Fragmentation attacks are described in chapter fifteen. Chapter sixteen reports on some odd looking non-malicious packets, in warning against reacting to false positives. A grab bag of odd packets is listed in chapter seventeen.

As should be evident from the description above, there is a good deal of valuable material in this book. Unfortunately, it is not easy to extract the useful bits. The book as a whole could use serious reorganization. While chapter one appears to be an introduction to the technical details, a far better explanation of packets and the import of various fields is given in chapter five, ostensibly on non- malicious or normal traffic, and this material should probably have been placed at the beginning of the manual. Chapter fourteen, almost at the end of the text, reviews buffer overflows, which are seen throughout the chapters preceding it. There is a slight attempt to explain the book in chapter two, but the content and organization is perplexing, there is heavy use of unilluminated insider jargon, and the presentation of example packets and subsequent conclusions without the middle step of identifying the items that make these data suspicious could be quite frustrating to the student. The new system administrator will not find the explanations clear or illuminating. The experienced professional will not find particular attacks or traffic types easy to find for reference. Both groups will find themselves flipping back and forth between sections of the book, or even between sections of the exegesis of one particular attack.

However, both groups will likely be interested in the book anyway, simply because of the lack of other sources.

copyright Robert M. Slade, 2003 BKINSIAN.RVW 20030831