Cisco Guard Configuration Guide (Software Version 5.0)
Understanding Attack Reports

Table Of Contents

Understanding Attack Reports

Understanding the Report Layout

General Details

Attack Statistics

Dropped/Replied Packets

Detected Anomalies

Mitigated Attacks

Spoofed Attacks

Zombie Attacks

Client Attacks

User-Defined Attacks

Malformed Packets

Zombies

Understanding the Report Parameters

Displaying Attack Reports

Exporting Attack Reports

Exporting Attack Reports Automatically

Exporting Attack Reports of All Zones

Exporting Zone Reports


Understanding Attack Reports


This chapter describes the attack reports that the Cisco Guard (Guard) produces and contains the following sections:

Understanding the Report Layout

Understanding the Report Parameters

Displaying Attack Reports

Exporting Attack Reports

Understanding the Report Layout

The Guard provides an attack report for each zone to help form a comprehensive view of the attack. An attack begins when the Guard produces the first dynamic filter and ends when no dynamic filter is in use and no new dynamic filters are added. Reports include details of the attacks that are organized into sections. Each section describes different aspects of the traffic flow during an attack. You can display reports of past attacks and ongoing attacks, and you can export reports to an FTP or a Secure FTP (SFTP) server.

Reports include the following information and are described in these sections:

General Details

Attack Statistics

Dropped/Replied Packets

Detected Anomalies

Mitigated Attacks

Zombies—This section is available only when you enter the show reports details and show zombies commands

General Details

The general details section of the attack report includes general information about an attack.

Table 9-1 describes the fields in this section of the report.

Table 9-1 Field Descriptions in General Details Section of Attack Report

Field
Description

Report ID

The identification number of the report.

Attack Start

Displays the date and time that the attack started.

Attack End

Displays the date and time that the attack ended. A value of "Attack in progress" indicates that there is an ongoing attack.

Attack Duration

Displays the duration of the attack.


Attack Statistics

The attack statistics section provides a general analysis of the zone traffic flow for various packets. Table 9-2 describes for the packet types.

Table 9-2 Packet Types 

Type
Description

Received

Specifies the total amount of the diverted traffic.

Forwarded

Specifies the legitimate traffic that the Guard forwarded on to the zone.

Replied

Specifies the traffic that the Guard anti-spoofing and anti-zombie mechanisms sent back to the source in a verification attempt.

Dropped

Specifies the traffic that the Guard dropped.


Dropped/Replied Packets

The dropped/replied packets section of the attack report analyzes the packets that the Guard dropped and sent back to the source in a verification attempt (replied). The report classifies the packets by their type (spoofed or malformed) and by the Guard function that handled them (filter types or the Rate Limiter function).

Table 9-3 describes the different types of dropped and replied packets.

Table 9-3 Types of Dropped/Replied Packets 

Type
Description

Rate Limiter

Specifies packets that were dropped because they exceeded the rate of traffic that is defined by user filters rate limit parameter and the zone rate-limit command as allowed to be injected to the zone.

Flex-Content Filters

Specifies packets that were dropped by the Flex-Content filters.

User Filters

Specifies packets that were dropped by the user filters.

Dynamic Filters

Specifies packets that were dropped by the dynamic filters.

Spoofed

Specifies packets that were that were identified by the Guard as spoofed packets or packets originated by zombies and, therefore, not injected to the zone. Spoofed packets are replied (bounced) packets to which no replies were received.

Malformed

Specifies packets that were analyzed as malformed because of their malformed structure or due to the Guard anti-spoofing functions.


Detected Anomalies

The detected anomalies section of the attack report provides details of the traffic anomalies that the Guard detected in the zone traffic. A flow is classified as being an anomaly when it requires the production of a Dynamic filter. These anomalies can occur infrequently or can turn into systematic DDoS attacks. The Guard clusters anomalies with the same type and flow parameters (such as source IP address and destination port) under one anomaly type.

Table 9-4 describes the different types of detected anomalies.

Table 9-4 Types of Detected Anomalies 

Type
Description

dns (tcp)

An attacking DNS-TCP protocol flow.

dns (udp)

An attacking DNS-UDP protocol flow.

fragments

A detected flow with an unusual amount of fragmented traffic.

http

An unusual HTTP traffic flow.

ip_scan

A detected flow initiated from a source IP address that tried to access many zone destination IP addresses.

other_protocols

A non-TCP/UDP attacking protocol flow.

port_scan

A detected flow initiated from a source IP address that tried to access many zone ports.

tcp_connections

A detected flow with an unusual number of TCP concurrent connections, with or without data.

tcp_incoming

A detected flow attacking a TCP service when the zone is a server.

tcp_outgoing

A detected flow consisting of SYN-ACK flood or other packet attacks on connections initiated by the zone when the zone is the client.

tcp_ratio

A detected flow with an unusual ratio between different types of TCP packets, for example, SYN packets as opposed to FIN/RST packets.

udp

An attacking UDP protocol flow.

unauthenticated_tcp

A detected flow that the Guard anti-spoofing functions have not succeeded in authenticating, for example, ACK flood, FIN flood, or any other flood of unauthenticated packets.

user

An anomaly flow that was detected by user definitions.


Mitigated Attacks

The mitigated attacks section of the attack report details the steps the Guard took to protect the zone (mitigated attacks). The report provides details of the timing of the mitigation and the type of mitigated attack. The Guard defines the mitigation type according to the functions that the Guard used to mitigate the attack. These functions indicate the attack type and sub-type.

For example, if the Guard uses a basic anti-spoofing function to mitigate an attacking flow of syn packets, the mitigated attack appears as spoofed/tcp_syn_basic. Spoofed indicates the attack type, and tcp_syn_basic indicates the attack sub-type.

There are five types of mitigated attacks:

Spoofed Attacks

Zombie Attacks

Client Attacks

User-Defined Attacks

Malformed Packets

Spoofed Attacks

Spoofed attacks include all traffic anomalies identified as a DDoS attack coming from a spoofed source. Table 9-5 describes the different types of spoofed attacks.

Table 9-5 Types of Spoofed Attacks 

Attack Type
Description

spoofed/tcp_syn (basic)

A flood of SYN packets that the basic anti-spoofing functions have not succeeded in authenticating.

spoofed/tcp_syn (strong)

A flood of SYN packets that the strong anti-spoofing functions have not succeeded in authenticating.

spoofed/tcp_syn_ack (basic)

A flood of syn_ack packets that the basic anti-spoofing functions have not succeeded in authenticating.

spoofed/tcp_syn_ack (strong)

A flood of syn_ack packets that the strong anti-spoofing functions have not succeeded in authenticating.

spoofed/tcp_incoming (basic)

A flood of traffic that the basic anti-spoofing functions have not succeeded in authenticating.

spoofed/
tcp_incoming (strong)

A flood of traffic that the strong anti-spoofing functions have not succeeded in authenticating.

spoofed/tcp_outgoing (strong)

A flood of traffic coming in response to zone initiated connections that the strong anti-spoofing functions have not succeeded in authenticating.

spoofed/udp (basic)

A flood of UDP traffic that the basic anti-spoofing functions have not succeeded in authenticating.

spoofed/udp (strong)

A flood of UDP traffic that the strong anti-spoofing functions have not succeeded in authenticating.

spoofed/other_protocols

A flood of other than TCP and UDP traffic that the Guard anti-spoofing functions have not succeeded in authenticating.

spoofed/tcp_fragments

A flood of TCP fragmented packets that the Guard anti-spoofing functions have not succeeded in authenticating.

spoofed/udp_fragments

A flood of UDP fragmented, packets that the Guard anti-spoofing mechanisms have not succeeded in authenticating.

spoofed /other_protocols_fragments

A flood of other than TCP and UDP fragmented packets that the Guard anti-spoofing mechanisms have not succeeded in authenticating.

spoofed/dns_queries (strong)

A flood of DNS queries packets that the strong anti-spoofing functions have not succeeded in authenticating.

spoofed/dns_replies (basic)

A flood of DNS packets coming in response to zone initiated connections that the basic anti-spoofing functions have not succeeded in authenticating.

spoofed/dns_replies (strong)

A flood of DNS packets coming in response to zone initiated connections that the strong anti-spoofing functions have not succeeded in authenticating.


Zombie Attacks

Zombie attacks include traffic anomalies identified as a DDoS attack originated by zombies. Table 9-6 describes the different types of zombie attacks.

Table 9-6 Types of Zombie Attacks

Attack Type
Description

zombie/http

A flood of HTTP traffic from many sources that were identified as non-spoofed, but the Guard anti-zombie functions have not succeeded in authenticating.


Client Attacks

Client attacks include all non-spoofed traffic anomalies. Table 9-7 describes the different types of client attacks.

Table 9-7 Types of Client Attacks 

Attack Type
Description

client_attack/tcp_connections

A flow with unusual number of TCP concurrent connections with or without data.

client_attack/http

A flood of HTTP traffic flow.

client_attack/tcp_ incoming

A flood attacking a TCP service when the zone is a server.

client_attack/tcp_outgoing

An attacking flood coming from authenticated IP connections that the zone initiated.

client_attack
/unauthenticated_tcp

A flood of ACKs, or FINs, or any other packets without a TCP handshake, or TCP connections that the Guard anti-spoofing functions have not succeeded in authenticating.

client_attack/dns (udp)

A flood of attacking DNS-UDP protocol flow.

client_attack/dns (tcp)

A flood of attacking DNS-TCP protocol flow.

client_attack/udp

A flood of attacking UDP protocol flow.

client_attack/other_protocols

A flood of non TCP/UDP attacking protocol flow.

client_attack/fragments

A flood of fragmented traffic.

client_attack/user

A user defined attack flood. The attack is defined by a dynamic filter that was added by a user.


User-Defined Attacks

User-defined attacks include all anomalies handled by the user filters. The use filters can either function by default or you can configure them manually. See "Configuring Policy Templates and Policies" for further details. Table 9-8 describes the different types of user-defined attacks.

Table 9-8 Types of User-Defined Attacks 

Attack Type
Description

user_defined/
user_filter_rate_limit

A flood that was dropped because it exceeded the rate limit defined for a user filter.

user_defined/
user_drop_filters

A flood that was dropped by user filters.

user_defined/rate_limit

A flood that was dropped due to one of the following:

It exceeded the rate limit defined for a user filter.

It exceeded the rate limit defined by the zone rate-limit command.

It exceeded the internal rate limit that is defined for unauthenticated TCP RST packets or unauthenticated DNS zone transfer packets.

user_defined/
flex_content_filter

A flood that was dropped by the flex-content filters.


Malformed Packets

Malformed packets include all traffic anomalies identified as consisting of maliciously malformed packets. Table 9-9 describes the different types of malformed packets.

Table 9-9 Types of Malformed Packets 

Attack Type
Description

malformed_packets /packets_to_proxy_ip

A flood attacking a Guard proxy IP address.

malformed_packets
/dns_anti_spoofing_algo

A flood of malformed packets due to the operation of the Guard DNS anti-spoofing functions.

malformed_packets
/dns (queries)

A flood of malformed DNS packets.

malformed_packets
/dns (short_queries)

A flood of short DNS queries.

malformed_packets
/dns (replies)

A flood of malformed DNS replies.

malformed_packets
/src ip = dst ip

A flood of packets with the zone IP address as their source and destination.

malformed_packets /zero_header_field

A flood of packets in which the port, protocol and IP fields in the header illegally equal zero.


Zombies

Zombie attacks include traffic anomalies identified as a DDoS attack originated by zombies. The Guard attack report displays a table listing zombies that are current attacking the zone. Use the show reports details and show zombies commands to display the list of currently attacking zombies.

See Table 9-15 for information about the fields in the show zombies command output.

Understanding the Report Parameters

Different sections of the report describe different aspects of the traffic flow.

Table 9-10 describes the fields for Attack Statistics and Dropped/Replied Packets.

Table 9-10 Field Descriptions for Attack Statistics 

Field
Description

Total Packets

Specifies the total number of attack packets.

Average pps

Specifies the average traffic rate in pps units.

Average bps

Specifies the average traffic rate in bps units.

Max. pps

Specifies the maximum traffic rate measured in pps units.

Max. bps

Specifies the maximum traffic rate measured in bps units.

Percentage

Specifies the number of forwarded, replied, and dropped packets as a percentage of the total received packets.


Table 9-11 describes the flow statistics for Detected Anomalies and Mitigated Attacks.

Table 9-11 Field Descriptions for Flow Statistics 

Field
Description

ID

Specifies the identification number (ID) of the detected anomaly.

Start time

Specifies the date and time that the anomaly was detected.

Duration

Specifies the duration of the anomaly in hours, minutes, and seconds.

Type

Specifies the type of anomaly or mitigated attack.

Triggering rate

Specifies the anomaly traffic rate that exceeded the policy
threshold.

% Threshold

Indicates the percentage by which the triggering rate is above the policy threshold.

Flow

Specifies the anomaly flow and mitigated attack flow. The
characteristics include the protocol number, source IP address, source port, destination IP address, and destination port. It indicates whether or not the traffic is fragmented. Any indicates that there is both fragmented and non-fragmented traffic.


A value of * for any of the parameters indicates one of the following:

The value is undetermined.

More than one value was measured for the anomaly parameter.

A value of #, followed by a number, for any of the parameters indicates the number of values measured for that parameter.

The Guard may display a value of notify on the right side of the flow description. A value of notify for any of the report rows indicates that the Guard produces a notification only for the type of traffic the row describes, and it does not take action.

Displaying Attack Reports

To display a list of attack reports for any specific zone or a more detailed report for a specific attack, enter the following command in zone configuration mode:

show reports [sub-zone-name] [current | report-id] [details]

Table 9-12 provides the arguments and keywords for the show reports command.

Table 9-12 Arguments and Keywords for the show reports Command  

Parameter
Description

sub-zone-name

(Optional) The name of a sub zone that was created from the zone. See the "Understanding Subzones" section for more information.

current

An attack that is in progress.

The number of bits and packets is not displayed for an ongoing attack. In reports of an attack in progress, the packets and bits fields have a value of zero (0).

report-id

The identification number of the report.

details

(Optional) Displays details of the flows and attacking zombies.


The following example shows how to view a list of all attacks on the zone:

user@GUARD-conf-zone-scannet# show reports 

Table 9-14 describes the fields in the show reports command output.

Table 9-13 Field Descriptions for the show reports
Command Output 

Field
Description

Report ID

The report identification number.

Attack Start

The date and time the attack started.

Attack End

The date and time the attack ended. A value of "Attack in progress" indicates that there an ongoing attack.

Attack Duration

The duration of the attack.

Attack Type

Type of mitigated attack. Possible values are as follows:

client_attack—All non-spoofed traffic anomalies.

malformed_packets—All traffic anomalies identified as consisting of maliciously malformed packets.

spoofed—Traffic anomalies identified as a DDoS attack coming from a spoofed source.

user_defined—All anomalies handled by the user filters. These can either function by default or be user configured.

zombie—Traffic anomalies identified as having been originated by zombies.

hybrid—An attack made up of several attacks with different characteristics.

traffic_anomaly—An anomaly that was only detected for a short period of time and therefore did not require mitigation.

Malicious Traffic

The sum of the number of packets the Guard identified as part of an attack and therefore dropped, and the number of packets to which the Guard sent replies to the initiating client in order to verify whether they are part of authentic traffic or part of an attack.


The following example shows how to display the report of the current attack on the zone:

user@GUARD-conf-zone-scannet# show reports current

The attack report displays the following output. For more information about the different sections, see the "Understanding the Report Layout" section.

Attack Start
:
Feb 26 2004 09:58:54
Attack End
:
Attack in progress
Attack Duration
:
00:08:34

Attack Statistics:

Total 
Packets
Average 
pps
Average 
bps
Max pps
Max bps
Percentage
Received
95878
186.53
110977.74
1455.44
914428.24
N/A
Forwarded
53827
104.72
64278.54
1430.85
899196.24
56.14
Replied
1870
3.64
2172.89
23.03
14433.88
1.95
Dropped
40181
78.17
44526.32
96.82
55010.13
41.91 


Dropped/Replied Packets:

Total 
Packets
Average 
pps
Average 
bps
Max pps
Max bps
Percentage
Rate Limiter
0
0
0
0
0
0
Flex-Content 
Filter
0
0
0
0
0
0
User Filters
0
0
0
0
0
0
Dynamic Filters 
40128
78.07
44473.53
96.82
55010.13
99.84

Spoofed
12
0.02
11.95
0.15
75.29
0.03
Malformed
53
0.1
52.79
1.56
798.12
0.13

Detected Anomalies:
ID
 Start Time
 Duration
 Type
Triggering 
Rate
%Threshold 
1
Feb 26 09:58:54
00:08:34
HTTP
997.44
897.44

Flow: 6 * 
*
92.168.100.34  80
no fragments

Mitigated Attacks:
ID
 Start Time
 Duration
 Type
Triggering 
Rate
%Threshold 
1
Feb 26 09:59:40
 00:07:59
client_attack/
tcp_connections 
 38 
 280

Flow: 6 (#52) 
*
92.168.200.254 80
no fragments

To display a more detailed report about the detected anomalies flow and the mitigated attacks flow, and to view a list of zombies attacks, use the details option.

Table 9-14 describes the flow fields in the detailed report.

Table 9-14 Field Descriptions of Flows in Detailed Report 

Field
Description

Detected Flow

Specifies the flow that caused the production of the Dynamic filter. The flow characteristics include the protocol number, source IP address, source port, destination IP address, and destination port, and an indication of whether the traffic is fragmented or not. Any indicates that there is both fragmented and non-fragmented traffic.

Action Flow

Specifies the flow that was addressed by the Dynamic filter. The action flow can have a wider range than the detected flow. For example, the detected flow could indicate a specific source port for a specific source IP address, whereas the action flow could indicate all source ports for the specified source IP address.

The flow characteristics include the protocol number, source IP address, source port, destination IP address, and destination port, and an indication of whether the traffic is fragmented or not. Any indicates that there is both fragmented and non-fragmented traffic.


Table 9-15 describes the fields in the detailed report about zombie attacks.

Table 9-15 Field Descriptions for Zombie Attacks Table

Field
Description

IP

The zombie IP address.

Start Time

The date and time that the zombie connection was initially identified.

Duration

The duration of the zombie attack.

#Requests

The number of HTTP get requests sent by the zombie.



Note If there are no zombie attacks, Report doesn't exist appears under the Zombies heading in the report.


Exporting Attack Reports

You can export attack reports to an FTP or an SFTP server for monitoring and diagnostics capabilities. You can export attack reports in text format or in Extensible Markup Language (XML) format.

This section includes the following topics:

Exporting Attack Reports Automatically

Exporting Attack Reports of All Zones

Exporting Zone Reports

Exporting Attack Reports Automatically

You can configure the Guard to export attack reports automatically, in XML format, at the end of an attack. The Guard exports the reports of any one of the zones when an attack on the zone ends. The XML schema is described in the ExportedReports.xsd file that accompanies the version.

You can download the .xsd files that accompany the version from the Software Center at:

http://www.cisco.com/public/sw-center/.

To configure the Guard to export attack reports automatically, enter one of the following commands in configuration mode:

export reports ftp server remote-path [login] [password]

export reports sftp server remote-path login


Note You must configure the SSH key that the Guard uses for SFTP communication before you enter the copy reports command. See the "Configuring the Key for SFTP Connections" section for more information.


Table 9-16 describes the arguments for the export reports command.

Table 9-16 Arguments for the export reports Command  

Parameter
Description

ftp

Exports the attack reports to an FTP server.

sftp

Exports the attack reports to an SFTP server.

server

The IP address of the server.

remote-path

The complete path of the directory where the files are saved.

login

The server login name.

The login argument is optional when you define an FTP server. When you do not insert a login name, the FTP server assumes an anonymous login and does not prompt you for a password.

password

(Optional) The password for the remote FTP server.


The following example shows how to automatically export reports (in XML format) at the end of an attack to an FTP server at IP address 10.0.0.191 by using login name user1 and password password1:

user@GUARD-conf# export reports ftp 10.0.0.191 /root/reports user1 
password1

Exporting Attack Reports of All Zones

You can export the attack reports of all zones in text or XML format by entering one of the following commands in global mode:

copy reports [details] [xml] ftp server full-file-name [login] [password]

copy reports [details] [xml] sftp server full-file-name login


Note You must configure the SSH key that the Guard uses for SFTP communication before you enter the copy reports command. See the "Configuring the Key for SFTP Connections" section for more information.


Table 9-17 provides the arguments and keywords for the copy reports command.

Table 9-17 Arguments and Keywords for the copy reports Command 

Parameter
Description

xml

(Optional) Export the report in XML format. The XML schema is described in the ExportedReports.xsd file that accompanies the version. You can download the .xsd files that accompany the version from the Software Center at: http://www.cisco.com/public/sw-center/.

By default, reports are exported in text format.

Reports in XML format include all details. If you include the xml option, it is not necessary to include the details option.

details

(Optional) Export details of flow and attacking source IP addresses.

ftp

Exports the attack reports to an FTP server.

sftp

Exports the attack reports to an SFTP server.

server

The IP address of the server.

full-file-name

The full name of the file. If you do not specify a path, the server saves the file in your home directory.

login

The server login name.

The login argument is optional when you define an FTP server. When you do not insert a login name, the FTP server assumes an anonymous login and does not prompt you for a password.

password

(Optional) The password for the remote FTP server.


The following example shows how to copy a list of all attacks handled by the Guard (in text format) to an FTP server at IP address 10.0.0.191 by using login name user1 and password password1:

user@GUARD# copy reports ftp 10.0.0.191 AGMreports.txt user1 password1

Exporting Zone Reports

To copy the attack reports of a specific zone to an FTP or SFTP server, enter one of the following commands in global mode:

copy zone zone-name reports [current | report-id] [xml] [details] ftp server full-file-name [login] [password]

copy zone zone-name reports [current | report-id] [xml] [details] sftp server full-file-name login


Note You must configure the SSH key that the Guard uses for SFTP communication before you enter the copy reports command. See the "Configuring the Key for SFTP Connections" section for more information.


Table 9-18 describes the arguments and keywords for the copy zone reports command.

Table 9-18 Arguments and Keywords for the copy zone reports
Command  

Parameter
Description

zone-name

The name of an existing zone.

current

(Optional) Export an ongoing attack report (if applicable).

The default is to export all zone reports.

report-id

(Optional) The ID of an existing report. The Guard exports the report with the specified ID number. To view the details of the zone attack reports, use the show zone reports command.

The default is to export all zone reports.

xml

(Optional) Export the report in XML format. The XML schema is described in the ExportedReports.xsd file that accompanies the version. You can download the .xsd files that accompany the version from the Software Center at: http://www.cisco.com/public/sw-center/.

The default is to export reports in text format.

Reports in XML format include all details. If you include the xml option, it is not necessary to include the details option.

details

(Optional) Export details of flow and attacking source IP addresses.

ftp

Exports the attack reports to an FTP server.

sftp

Exports the attack reports to an SFTP server.

server

The IP address of the server.

remote-path

The complete path of the directory where the files are saved.

login

The server login name.

The login argument is optional when you define an FTP server. When you do not insert a login name, the FTP server assumes an anonymous login and does not prompt you for a password.

password

(Optional) The password for the remote FTP server.


The following example shows how to copy all attack reports on the zone to an FTP server at IP address 10.0.0.191 by using login name user1 and password password1:

user@GUARD# copy zone scannet reports ftp 10.0.0.191 
ScannetCurrentReport.txt user1 password1