![32
PING Sweeps
TCP Sweeps
Server
Client
C(SYN:PortNo & ISN)
S (SYN & ISN) + ACK[ C (SYN+!) ]
RESET (not active)
S(ISN+1)
When will a RESET be sent?
When RFC does not appear correct while appearing.
RFC = (Destination (IP + port number) & Source( IP & port
number))](https://image.slidesharecdn.com/modul2-footprintingscanningenumeration-220905051358-38e21bf5/85/Modul-2-Footprinting-Scanning-Enumeration-ppt-32-320.jpg)
Modul 2 - Footprinting Scanning Enumeration.ppt
- 1. 1 Modul 2 Footprinting Scanning Enumeration Isbat Uzzin Nadhori Informatical Engineering PENS-ITS Politeknik Elektronika Negeri Surabaya ITS - Surabaya
- 2. 2 Intelligence Gathering Techniques 3 Major Steps Foot Printing Scanning Enumeration Similar to Military Gather information on the target Analyze weaknesses Construct and launch attack
- 3. 3 Gathering Process Overview You can’t attack what you don’t know
- 8. 8 Footprinting Footprinting is the ability to obtain essential information about an organization. Commonly called network reconnaissance. Result Gather information includes: –The technologies that are being used such as, Internet, Intranet, Remote Access and the Extranet. –To explored the security policies and procedures –take an unknown quality and reduce it –Take a specific range of domain names, network blocks and individual IP addresses of a system that is directly connected to the Internet This is done by employing various computer security techniques, as: • DNS queries nslookup, dig, Zone Transfer • Network enumeration • Network queries • Operating system identification • Organizational queries When used in the computer security lexicon, "footprinting" generally refers to one of the pre-attack phases; tasks performed prior to doing the actual attack. Some of the tools used for footprinting areSam Spade, nslookup, traceroute, Nmap and neotrace. • Ping sweeps • Point of contact queries • Port Scanning • Registrar queries (WHOIS queries) • SNMP queries • World Wide Web spidering
- 9. 9 DNS Query
- 10. 10 Network Query Tools * Ping * NSlookup * Whois * IP block search * Dig * Traceroute * Finger * SMTP VRFY * Web browser keep-alive * DNS zone transfer * SMTP relay check * Usenet cancel check * Website download * Website search * Email header analysis * Email blacklist * Query Abuse address
- 11. 11 Information to Gather Attacker’s point of view Identify potential target systems Identify which types of attacks may be useful on target systems Defender’s point of view Know available tools May be able to tell if system is being footprinted, be more prepared for possible attack Vulnerability analysis: know what information you’re giving away, what weaknesses you have
- 14. 14 Tools - Linux Some basic Linux tools - lower level utilities Local System hostname ifconfig who, last Remote Systems ping traceroute nslookup, dig whois arp, netstat (also local system) Other tools lsof
- 15. 15 Tools – Linux (2) Other utilities wireshark (packet sniffing) nmap (port scanning) - more later Ubuntu Linux Go to System / Administration / Network Tools – get interface to collection of tools: ping, netstat, traceroute, port scan, nslookup, finger, whois
- 16. 16 Tools - Windows Windows Sam Spade (collected network tools) Wireshark (packet sniffer) Command line tools ipconfig Many others…
- 17. 17 Traceroute # traceroute ns1.target-company.com traceroute to ns1.target-company.com (xxx.xx.xx.xx), 30 hops max, 40 byte packets 1 fw-gw (209.197.192.1) 0.978 ms 0.886 ms 0.875 ms 2 s1-0-1-access (209.197.224.69) 4.816 ms 5.275 ms 3.969 ms 3 dallas.tx.core1.fastlane.net (209.197.224.1) 4.622 ms 9.439 ms 3.977 ms 4 atm8-0-024.CR-1.usdlls.savvis.net (209.44.32.217) 6.564 ms 5.639 ms 6.681 ms 5 Serial1-0-1.GW1.DFW1.ALTER.NET (157.130.128.53) 7.148 ms 6.595 ms 7.371 ms 6 103.ATM3-0.XR2.DFW4.ALTER.NET (146.188.240.38) 11.861 ms 11.669 ms 6.732 ms 7 152.63.96.85 (152.63.96.85) 10.565 ms 25.423 ms 25.369 ms 8 dfw2-core2-pt4-1-0.atlas.digex.net (206.181.125.153) 13.289 ms 10.585 ms 17.173 ms 9 dfw2-core1-fa8-1-0.atlas.digex.net (165.117.52.101) 44.951 ms 241.358 ms 248.838 ms 10 swbell-net.demarc.swbell.net (206.181.125.10) 12.242 ms 13.821 ms 27.618 ms 11 ded2-fa1-0-0.rcsntx.swbell.net (151.164.1.137) 25.299 ms 11.295 ms 23.958 ms 12 target-company-818777.cust-rtr.swbell.net (151.164.x.xxx) 52.104 ms 24.306 ms 17.248 ms 13 ns1.target-company.com (xxx.xx.xx.xx) 23.812 ms 24.383 ms 27.489 ms
- 18. 18 Traceroute - Network Mapping cw swb Internet Routers
- 19. 19 Traceroute - Network Mapping cw swb Internet Routers
- 20. 20 Traceroute - Network Mapping Firewall DMZ cw swb VPN Internet Routers
- 21. 21 Traceroute - Network Mapping Firewall DMZ www ftp cw swb VPN Internet Routers
- 22. 22 Traceroute - Network Mapping Firewall DMZ www ftp cw swb VPN Internet Routers
- 23. 23 Traceroute - Network Mapping Sun Linux Firewall NT Hosts Inside DMZ www ftp cw swb VPN Internet Routers
- 24. 24 Traceroute - Network Mapping Sun Linux Firewall NT Hosts Inside DMZ www ftp cw swb VPN Internet Routers Linux 2.0.38 xxx.xx.48.2 AIX 4.2.1 xxx.xx.48.1 Checkpoint Firewall-1 Solaris 2.7 xxx.xx.49.17 Checkpoint Firewall-1 Nortel VPN xxx.xx.22. 7 Cisco 7206 204.70.xxx.xxx Nortel CVX1800 151.164.x.xxx IDS?
- 25. 25 Domain Name: UWEC.EDU Registrant: University of Wisconsin - Eau Claire 105 Garfield Avenue Eau Claire, WI 54702-4004 UNITED STATES Contacts: Administrative Contact: Computing and Networking Services 105 Garfield Ave Eau Claire, WI 54701 UNITED STATES (715) 836-5711 networking@uwec.edu Name Servers: TOMATO.UWEC.EDU 137.28.1.17 LETTUCE.UWEC.EDU 137.28.1.18 BACON.UWEC.EDU 137.28.5.194 Whois
- 26. 26 Scanning
- 27. 27 Introduction Scanning can be compared to a thief checking all the doors and windows of a house he wants to break into. Scanning- The art of detecting which systems are alive and reachable via the internet and what services they offer, using techniques such as ping sweeps, port scans and operating system identification, is called scanning. The kind of information collected here has to do with the following: 1) TCP/UDP services running on each system identified. 2) System architecture (Sparc, Alpha, x86) 3) Specific IP address of systems reachable via the internet. 4) Operating System type.
- 28. 28 Ping Sweeps ping sweep is a method that can establish a range of IP addresses which map to live hosts. ICMP Sweeps (ICMP ECHO requests) Broadcast ICMP Non Echo ICMP TCP Sweeps UDP Sweeps
- 29. 29 PING SWEEPS ICMP SWEEPS ICMP ECHO request ICMP ECHO reply Target alive Intruder Querying multiple hosts – Ping sweep is fairly slow Examples UNIX – fping and gping WINDOWS - Pinger
- 30. 30 Broadcast ICMP Intruder Network ICMP ECHO request ICMP ECHO reply ICMP ECHO reply ICMP ECHO reply Can Distinguish between UNIX and WINDOWS machine UNIX machine answers to requests directed to the network address. WINDOWS machine will ignore it.
- 31. 31 PING SWEEPS NON – ECHO ICMP Example ICMP Type 13 – (Time Stamp) Originate Time Stamp - The time the sender last touched the message before sending Receive Time Stamp - The echoer first touched it on receipt. Transmit Time Stamp - The echoer last touched on sending it.
- 32. 32 PING Sweeps TCP Sweeps Server Client C(SYN:PortNo & ISN) S (SYN & ISN) + ACK[ C (SYN+!) ] RESET (not active) S(ISN+1) When will a RESET be sent? When RFC does not appear correct while appearing. RFC = (Destination (IP + port number) & Source( IP & port number))
- 33. 33 PING Sweeps Depends on ICMP PORT UNREACHABLE message. UDP data gram ICMP PORT UNREACHABLE Unreliable because • Routers can drop UDP packets •UDP services may not respond when correctly probed •Firewalls are configured to drop UDP •Relies on fact that non-active UDP port will respond Target System
- 34. 34 PORT SCANNING Types: TCP Connect() Scan TCP SYN Scan( Half open scanning) Stealth Scan Explicit Stealth Mapping Techniques SYN/ACL , FIN, XMAS and NULL Inverse Mapping Reset Scans, Domain Query Answers Proxy Scanning / FTP Bounce Scanning TCP Reverse Ident Scanning
- 35. 35 Port Scanning Types TCP Connect() Scan SYN packet SYN/ACK listening RST/ACK (port not listening) SYN/ACK A connection is terminated after the full length connection establishment process has been completed
- 36. 36 Port Scanning Type TCP SYN Scan (half open scanning) SYN packet SYN/ACK listening RST/ACK (port not listening) We immediately tear down the connection by sending a RESET
- 37. 37 Port Scanning Type Stealth Scan A scanning technique family doing the following Pass through filtering rules. Not to be logged by the targeted system logging mechanism Try to hide themselves at the usual site / network traffic. The frequently used stealth mapping techniques are. SYN/ACK scan FIN scans XMAS scans NULL scans
- 38. 38 PORT Scanning Techniques: Random Port scan Slow Scan Fragmentation Scanning Decoy Coordinated Scans
- 39. 39 PORT Scanning “Random” Port Scan Randomizing the sequence of ports probed may prevent detection. Slow Scan Some hackers are very patient and can use network scanners that spread out the scan over a long period of time. The scan rate can be, for example, as low as 2 packets per day per target site. Fragmentation scanning In case of TCP the 8 octets of data (minimum fragment size) are enough to contain the source and destination port numbers. This will force the TCP flags field into the second fragment. Decoy Some network scanners include options for Decoys or spoofed address in their attacks. Coordinated Scans If multiple IPs probe a target network, each one probes a certain service on a certain machine in a different time period, and therefore it would be nearly impossible to detect these scans.
- 40. 40 Operating System Detection Banner Grabbing DNS HINFO Record TCP/IP Stack Fingerprinting
- 42. 42 Operating System Detection DNS HINFO Record The host information record is a pair of strings identifying the host’s hardware type and the operating system www IN HINFO “Sparc Ultra 5” “Solaris 2.6” One of the oldest technique
- 43. 43 Operating System Detection TCP/IP Finger Printing The ideas to send specific TCP packets to the target IP and observe the response which will be unique to certain group or individual operations. Types of probes used to determine the OS type The FIN Probe, The Bogus Flag Probe, TCP initial sequence number sampling, Don’t Fragment bit, TCP initial window, ACK value, ICMP error Message Quenching, ICMP message quoting, ICMP error message Echoing Integrity, Type of service, fragmentation handling, TCP options
- 44. 44 Firewalking Gather information about a remote network protected by a firewall Purpose Mapping open ports on a firewall Mapping a network behind a firewall If the firewall’s policy is to drop ICMP ECHO Request/Reply this technique is very effective.
- 45. 45 How does Firewalking work? It uses a traceroute-like packet filtering to determine whether or not a particular packet can pass through a packet-filtering device. Traceroute is dependent on IP layer(TTL field), any transport protocol can be used the same way(TCP, UDP, and ICMP).
- 46. 46 What Firewalking needs? The IP address of the last known gateway before the firewall takes place. Serves as WAYPOINT The IP address of a host located behind the firewall. Used as a destination to direct packet flow
- 47. 47 Getting the Waypoint If we try to traceroute the machine behind a firewall and get blocked by an ACL filter that prohibits the probe, the last gateway which responded(the firewall itself can be determined) Firewall becomes the waypoint.
- 48. 48 Getting the Destination Traceroute the same machine with a different traceroute-probe using a different transport protocol. If we get a response That particular traffic is allowed by the firewall We know a host behind the firewall. If we are continuously blocked, then this kind of traffic is blocked. Sending packets to every host behind the packet- filtering device can generate an accurate map of a network’s topology.
- 49. 49 How to identify/avoid threats? Long-standing rule for Unix System administrators to turn off any services that aren’t in use For personal workstations! Hackers have access to utilities to scan the servers but so do you!. Hackers look in for open ports. So we can our servers first and know what the hackers will see and close any ports that shouldn’t be open.
- 50. 50 Some tools to help us Nmap It is a utility that scans a particular server and informs us which ports are open. Ethereal It is a utility that will scan the network and help us decode what is going on. We can watch the network traffice and find out if hackers can see anything that will help them break into our systems.
- 51. 51 Enumeration
- 52. 52 52 Introduction to Enumeration Enumeration extracts information about: –Resources or shares on the network –User names or groups assigned on the network –Last time user logged on –User’s password Before enumeration, you use Port scanning and footprinting –To Determine OS being used Intrusive process
- 53. 53 53 NBTscan NBT (NetBIOS over TCP/IP) –is the Windows networking protocol –used for shared folders and printers NBTscan –Tool for enumerating Microsoft OSs
- 54. 54 54 Null Session Information Using these NULL connections allows you to gather the following information from the host: –List of users and groups –List of machines –List of shares –Users and host SIDs (Security Identifiers) •From brown.edu (link Ch 6b)
- 55. 55 55 Demonstration of Null Sessions Start Win 2000 Pro Share a folder From a Win XP command prompt –NET VIEW ip-address Fails –NET USE ip-addressIPC$ "" /u:"" •Creates the null session •Username="" Password="" –NET VIEW ip-address Works now
- 56. 56 56 Demonstration of Enumeration Download Winfo from link Ch 6g Run it – see all the information!
- 57. 57 57 NetBIOS Enumeration Tools Net view command –Shows whether there are any shared resources on a network host
- 58. 58 58 NetBIOS Enumeration Tools (continued) Net use command –Used to connect to a computer with shared folders or files
- 59. 59 Net use
- 60. 60
- 61. 61 61 Additional Enumeration Tools NetScanTools Pro DumpSec Hyena NessusWX
- 62. 62 62 NetScanTools Pro Produces a graphical view of NetBIOS running on a network Enumerates any shares running on the computer Verifies whether access is available for shared resource using its Universal Naming Convention (UNC) name Costs about $250 per machine (link Ch 6i)
- 63. 63 63
- 64. 64 64
- 65. 65 65 DumpSec Enumeration tool for Microsoft systems Produced by Foundstone, Inc. Allows user to connect to a server and “dump” the following information –Permissions for shares –Permissions for printers –Permissions for the Registry –Users in column or table format –Policies and rights –Services
- 66. 66 DumpSec
- 67. 67 67 Hyena Excellent GUI product for managing and securing Microsoft OSs Shows shares and user logon names for Windows servers and domain controllers Displays graphical representation of: –Microsoft Terminal Services –Microsoft Windows Network –Web Client Network –Find User/Group
- 68. 68 68
- 69. 69 69 NessusWX This is the client part of Nessus Allows enumeration of different OSs on a large network Running NessusWX –Be sure Nessus server is up and running –Open the NessusWX client application –To connect your client with the Nessus server •Click Communications, Connect from the menu on the session window •Enter server’s name •Log on the Nessus server
- 70. 70 70
- 71. 71 71
- 72. 72 72 NessusWX (continued) Nessus identifies –NetBIOS names in use –Shared resources –Vulnerabilities with shared resources •Also offers solutions to those vulnerabilities –OS version –OS vulnerabilities –Firewall vulnerabilities
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- 74. 74 74
- 75. 75 75
- 76. 76 76
- 77. 77 77 Enumerating the *NIX Operating System Several variations –Solaris –SunOS –HP-UX –Linux –Ultrix –AIX –BSD UNIX –FreeBSD –OpenBSD
- 78. 78 78 UNIX Enumeration Finger utility –Most popular tool for security testers –Finds out who is logged in to a *NIX system –Determine owner of any process Nessus –Another important *NIX enumeration tool
- 79. 79 79
- 80. 80 80
- 81. 81 Footprinting And Enumeration using netcraft.com