24-06-2011, 10:52 AM
Presented By-
Nikhil Singh(54)
Anshu Gupta(16)
Julee Dutta(59)
Ethical Hacking
PHASES OF HACKING
Reconnaissance- preparatory phase ,gather information
Scanning-scan target system
Gaining Access-vulnerability discovered ,real hacking
Maintaining Access-active access for future attack
Covering Tracks-remove all traces of attack
Using free Sites
WEB SERVER
WAYS OF DOS ATTACK
PING OF DEATH
TEARDROP
SYN ATTACK
LAND ATTACK
PING OF DEATH
In this attack, the target system is pinged with a data packet that exceeds the maximum bytes allowed by TCP/IP, which is 65 536. This would have almost always caused the remote system to hang, reboot or crash.
The following Ping command creates a giant datagram of the size 65540 for Ping. It might hang the victim's computer:
C:\windows>ping -l 65540
TEARDROP ATTACK
The Teardrop attack exploits the vulnerability present in the reassembling of data packets.
Consider the following scenario-: (Note: _ _ _ = 1 Data Packet)
Normally a system receives data packets in the following form, with no overlapping Offset values.
_ _ _ _ _ _ _ _ _
(1 to 1500 bytes) (1501 to 3000 bytes) (3001 to 4500 bytes)
Now in a Teardrop attack, the data packets are sent to the target computer in the following format:
_ _ _ _ _ _ _ _ _
(1 to 1500 bytes) (1500 to 3000 bytes) (1001 to 3600 bytes)
When the target system receives something like the above, it simply cannot handle it and will crash or hang or reboot.
SYN ATTACK
The SYN attack exploits TCP/IP's three-way handshake. Thus in order to understand as to how SYN Attacks work, you need to first knows how TCP/IP establishes a connection between two systems.
1. Client --------SYN Packet--------------à Host
2. Host -------------SYN/ACK Packet----------à Client
3. Client --------------ACK-----------------------à Host
In a SYN attack, several SYN packets are sent to the server but all these SYN packets have a bad source IP Address.
They queue up, use up resources and memory or the target system and eventually crash, hang or reboot the system.
Land Attacks
A Land attack is similar to a SYN attack, the only difference being that instead of a bad IP Address, the IP address of the target system itself is used. This creates an infinite loop between the target system and the target system itself.
CALL FORGING
SMS FORGING
Technology Involved
Routing the sms through international gateways.
Message id is spoofed at international gateway.
Finally SMS is routed to destination SMs centre number.
As there is no authentication involved ,it is sent to destination number with spoofed id
your credit card number to any site that is not secured, to guard against frauds.
It is better to use a security program that gives control over the cookies and send information back to the sites as leaving the cookies unguarded might prove fatal
Website owners should watch traffic and check any irregularity on the site.Putting host-based intrusion detection devices on the server may do this.
Use of firewalls may be beneficial.
Nikhil Singh(54)
Anshu Gupta(16)
Julee Dutta(59)
Ethical Hacking
PHASES OF HACKING
Reconnaissance- preparatory phase ,gather information
Scanning-scan target system
Gaining Access-vulnerability discovered ,real hacking
Maintaining Access-active access for future attack
Covering Tracks-remove all traces of attack
Using free Sites
WEB SERVER
WAYS OF DOS ATTACK
PING OF DEATH
TEARDROP
SYN ATTACK
LAND ATTACK
PING OF DEATH
In this attack, the target system is pinged with a data packet that exceeds the maximum bytes allowed by TCP/IP, which is 65 536. This would have almost always caused the remote system to hang, reboot or crash.
The following Ping command creates a giant datagram of the size 65540 for Ping. It might hang the victim's computer:
C:\windows>ping -l 65540
TEARDROP ATTACK
The Teardrop attack exploits the vulnerability present in the reassembling of data packets.
Consider the following scenario-: (Note: _ _ _ = 1 Data Packet)
Normally a system receives data packets in the following form, with no overlapping Offset values.
_ _ _ _ _ _ _ _ _
(1 to 1500 bytes) (1501 to 3000 bytes) (3001 to 4500 bytes)
Now in a Teardrop attack, the data packets are sent to the target computer in the following format:
_ _ _ _ _ _ _ _ _
(1 to 1500 bytes) (1500 to 3000 bytes) (1001 to 3600 bytes)
When the target system receives something like the above, it simply cannot handle it and will crash or hang or reboot.
SYN ATTACK
The SYN attack exploits TCP/IP's three-way handshake. Thus in order to understand as to how SYN Attacks work, you need to first knows how TCP/IP establishes a connection between two systems.
1. Client --------SYN Packet--------------à Host
2. Host -------------SYN/ACK Packet----------à Client
3. Client --------------ACK-----------------------à Host
In a SYN attack, several SYN packets are sent to the server but all these SYN packets have a bad source IP Address.
They queue up, use up resources and memory or the target system and eventually crash, hang or reboot the system.
Land Attacks
A Land attack is similar to a SYN attack, the only difference being that instead of a bad IP Address, the IP address of the target system itself is used. This creates an infinite loop between the target system and the target system itself.
CALL FORGING
SMS FORGING
Technology Involved
Routing the sms through international gateways.
Message id is spoofed at international gateway.
Finally SMS is routed to destination SMs centre number.
As there is no authentication involved ,it is sent to destination number with spoofed id
your credit card number to any site that is not secured, to guard against frauds.
It is better to use a security program that gives control over the cookies and send information back to the sites as leaving the cookies unguarded might prove fatal
Website owners should watch traffic and check any irregularity on the site.Putting host-based intrusion detection devices on the server may do this.
Use of firewalls may be beneficial.
