Download Threats in the Digital World

External Threats
-People & Technology
Rudeyna Quadri
February 11, 2003
Thursday, May 25,
2017
Outline
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Threats in the Digital World
People in the Digital World
Prelude to Hacking
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Footprinting
Scanning
Enumeration
Threats in the Digital World
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They mirror the threats in the physical world
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Digital embezzlement
Digital bank robbery
Invasion of privacy
Theft
Racketeering
Vandalism
Exploitation
Extortion
fraud
Threats in the Digital World
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Changing nature of the attacks
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Attacks may have same goals and share a
lot of the techniques with the physical
world, they are very different
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More common
More widespread
Harder to track
Effects will be more devastating
Real-Life Lessons
What happened:
Front page
replaced
How: Two years
since server code
was updated
Lesson: Update
systems frequently
Source: Internet World
What happened: Home
page text replaced
How: Failed to update
operating system in
timely fashion
Lesson: Always apply
latest patches
What happened: Customer
details compromised on
web site
How: Glitch on the web site
Lesson: Usage of stronger
customer authentication
needed & development
control processes
Threats in the Digital World
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Internet has three features which make
the threats more horrifying
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Automation
Action at a Distance
Technique Propogation
Automation
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Computer excel at dull, repetitive tasks
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Salami Attack
Fast automation makes attacks with a
minimal rate of return profitable
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Even a success rate of 1 in 10,000 is
acceptable
Violation of privacy
Action At a Distance
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Internet has no borders..every two points are
adjacent
Internet hackers don’t have to be anywhere
near their prey
Finding attackers sometime becomes
impossible
Lack of uniform international laws make it
harder to track cyber criminals across national
borders.
Technique Propagation
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Electronic counterfeiter
Only the first attacker has to be
skilled..everyone else can use his/her
software
Threats to the Digital
World..People
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Who are the adversaries in the digital
world?
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We can categorize them in several ways
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Objectives
Access
Resources
Expertise
Risk
Objectives
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Raw damage
Financial gain
Information
Levels of Access, resource &
Expertise
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Insider has much more access than
someone outside the organization
Access to different levels of resources:
some are well funded, while others
operate on a shoestring
Some have technical expertise while
others have none
Levels of Risk
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Risk tolerance is varied
Publicity seekers probably won’t want to
go to jail.
Definitions
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Risk = Threat X Vulnerability
Being “at risk" is being exposed to threats.
Risks are subjective -- the potential to incur consequences of
harm or loss of target assets.
A Risk Factor is the likelihood of resources being attacked.
Threats are dangerous actions that can cause harm.
The degree of threat depends on the attacker's Skills,
Knowledge, Resources, Authority, and Motives.
Vulnerabilities are weaknesses in victims that allow a threat
to become effective.
Hacker Jargons (Some)
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A rogue user is an authorized user who, without permission,
accessesrestricted assets.
A bogie is an unauthorized user who subverts security systems.
A cracker breaks into others’ computing facilities for their own
personal gain - be it financial, revenge, or amusement.
A hacktivist is a cracker with a cause. (Example of hactivism:
Building Peekabooty to get around governments blocking
websites)
A terrorist uses fear to blackmail others into doing what they
want.
Hacking Jargons (Some)
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White Hats are also called “ethical" hackers, such as the Axent
(now Symantec) Tiger Team
Black Hats disregard generally accepted social conventions and
laws.
Script kiddie is a derogatory term for a wannabe cracker who
lacks programming skills and thus relies on prewritten scripts
and toolkits for their exploits.
Journeyman is an experienced hacker: someone who has
collected many tools and made many connections.
A Puppet Master (wizard) produces exploits.
Source: http://www.wilsonmar.com/1secvul.htm
Types of Adversaries
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The Hacker
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FBI Seeks Hacker Who Stole eBay Info
Sat Feb 8,10:50 AM ET CHARLOTTE, N.C. A hacker used a University of North
Carolina computer system to steal
personal financial information from eBay
users, and at least one person lost money,
the FBI (news - web sites) said Friday.
The Hacker
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“Cracker” for the bad guys– “Hacker for the
good ones
Today’s hackers are
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Twenty-something & younger
Usually male
Have their own counterculture
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Hacker names, handles, lingo, rules
Only a small percentage of the hackers are
actually smart.
The Hacker
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Hacker stereotyped
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Real hackers have an understanding of
technology at a basic level. The rest are
called lames or Script Kiddies
Usually have a lot of time but limited
financial resources
The Hacker
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Hackers write hacking tools which can
automate the process of breaking into
systems.
Lone Criminals
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Lone criminals cause the bulk of
computer related crimes
Maybe insiders who notice a flaw in the
system & decide to exploit
Lone criminals will usually target
commerce systems.
Malicious Insiders
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Someone in the system who wants to attack
Perimeter defense not relevant
Not always attack system
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1991: employees in Charles Scwab in SF used
company’s e-mail system to buy and sell cocaine.
Insiders are not necesarrily employess.
Maybe:
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Contractors
Consultants
Insider Attack
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Most of the security measures are
powerless against insiders. Systems are
more vulnerable to them
Motivational factors for Insiders:
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Revenge
Financial Gain
Institutional Change
Publicity
Other Adversaries
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Industrial Spy:
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Precise motivation of gaining edge over competitors
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admissions administrator at Princeton broke into a Yale
admissions computer to look at student applicant records.
Source: http://www.all.net/
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Press:
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Subspecies of industrial spy, but different motivation—
creating sensation.
Organized Crime:
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Use technology in two ways:
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New Venue for crime: Hacking tools to break into bank
computers, stealing cell phone ID’s and reselling them.
Uses computers to assist in its core business.
Other Adversaries
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Police
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Information gathering
Have legal right to “eavesdrop” (with warrant)
No guarantee that the information will be used
ethically in the future.
Terrorist
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More concerned with causing harm than
information gathering
Denial of Service, and outright destruction.
Other Adversaries
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National Intelligence Organizations
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CIA, NSA, KGB, MI5, MI6
Usually extremely well funded
Some national intelligence organizations
are involved in industrial espionage and
passing on the info to their national
companies.
Infowarriors
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Military adversary who targets enemy’s
information or network infrastructure.
Attacks range from subtly modifying systems
so that they do not work to blowing up the
system.
Usually have the resources of the government
behind.
More short term goal oriented
Higher risk tolerance.
Hacking..first steps
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Before in-depth hacking can be
performed, three essential tasks must
be completed
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Footprinting
Scanning
Enumerating
Footprinting
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Create a complete profile of an organization’s
security posture
Steps
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Determine the scope of activities
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Network Enumeration
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Check organization’s website for info
Review HTML source code for comments
Identify domain names and associated networks
DNS Interrogation
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Query the DNS
Zone Transfer
Scanning
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Footprinting provides a list of network
and IP addresses through whois queries
Scanning determines what systems are
alive and reachable from the Internet
Scanning
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Tools for Scanning
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Ping Sweeps
Port Scans
Automated Discovery Tools
Scanning – Ping Sweeps
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One of the basic steps in mapping out a
network is performing an automated
ping sweep on a range of IP addresses.
Ping traditionally sends ICMP ECHO to
elicit an ICMP ECHO REPLY
Tools for Ping Sweeps
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fping
 Operates in UNIX
 Available in http://www.fping.com
 uses the Internet Control Message Protocol (ICMP)
echo request to determine if a host is up.
 “fping is different from ping in that you can specify
any number of hosts on the command line, or
specify a file containing the lists of hosts to ping.
Instead of trying one host until it timeouts or
replies, fping will send out a ping packet and
move on to the next host in a round-robin fashion.
If a host replies, it is noted and removed from the
list of hosts to check. If a host does not respond
within a certain time limit and/or retry limit it will
be considered unreachable”
Tools for Ping Sweeps
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Pinger
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Freeware for Windows
http://www.nmrc.org/files/snt/#chk-scan
Like fping, Pinger sends out multiple ICMP
ECHO packets in parralel and waits and
listens for responses.
Allows user to resolve hostnames and save
output to file
Tools for Ping Sweeps
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For Windows
WS_Ping ProPack
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www.ipswitch.com
Price
Single User
$37.50
10 User Pack $280
20 User Pack $540
50 User Pack $1,300
100 User Pack$2,450
Source: www.ipswitch.com
Price withService Agreement
$87.50
$330
$637
$1,534
$2,891
Ping Sweep
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Other Devices
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NMAP provides Ping Sweep facilities
Icmpenum from Simple Nomad
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Special feature
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ICMP TIME STAMP REQUEST
ICMP INFO REQUEST
Can use spoofed packets to avoid detection
Ping Sweep Countermeasures
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Detection
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Through network based IDS like snort
Other Unix-Based:
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Scanlogd, Ippl 1.4.14 etc.
Windows based
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Genius( freeware): detects TCP Scan to a
particular port
BlackIce (Commercial)
Ping Sweep Countermeasures
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Prevention
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Carefully evaluate the ICMP traffic to allow
in the network or into specific systems.
ICMP Traffics can be limited with ACLs to
specific IP addresses of the ISP.
Port Scanning
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Process of connecting to TCP and UDP ports
on the target system to determine what
services are running or are in a LISTENING
state
Three main objectives:
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Identify both the TCP and UDP services running
on the target system
Identify the type of operating system
Identify specific application or versions of an
operating system.
Port Scanning
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Types of port scan
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TCP connect scan: connects to the target port
and completes a full three-way hand-shake (SYN,
SYN/SCK, and ACK). Easily detected by the target
system.
TCP SYN scan: SYN packet sent to the target
port, if SYN/ACK is received, it is in listening state.
If RST/ACK received, port is not listening.
Stealthier than full scan, and may not be logged
by the target system.
Types of Port Scan
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TCP Fin Scan: sends a FIN packet to the target
port, target port sends back RST for all closed ports.
Usually only works on Unix based TCP/IP stacks.
TCP Xmas Tree scan: sends a FIN, URG and PUSH
packet to the target port. Target sends back RST for
all closed ports.
TCP Null Scan: turns off all flags. Targeyt system
sends back RST for all closed ports.
TCP ACK Scan: used to map out firewall rulesets.
Helps determine if firewall is stateless or stateful
Port Scanning Toolkit
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Unix Based:
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Strobe:
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TCP Port Scanning Utility
One of the fastest and most reliable
Optimizes system and network resources and scan target
system efficiently.
We only see half the picture as Strobe does not provide
UDP scanning capabilities.
UDP_scan
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Reliable
Sometimes triggers a message from major IDS
products..not stealthy
Port Scanning Toolkit
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Unix based
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Netcat
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Provides both TCP and UDP scanning abilities
Network Mapper (NMAP)
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Nmap can scan a system or an entire network
Possible to save output to a file
Able to launch decoy scans
Can do identity scanning
Port Scanning Toolkit
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Windows Based
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Port Probe (From NetScan Tools Pro 2003)
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SuperScan & WinScan
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TCP Port scanner
Free
ipEye
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Target IP & portlists can be imported from files.
TCP & UDP Scan
Performs source port scanning, as well as SYN, FIN and
Xmas tree scans.
Windows UDP Port Scanner (WUPS).
Port Scanning
Countermeasures
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Detection
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Detecting port scan activity is important to
understand when an attack may occur and
by whom. Primary methods for detection
are network based IDS programs like:
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Internet Security Sytems’ Real Secure
Snort
Port Scanning
Countermeasures
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Detection
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Unix Host based perspective:
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Scanlogd: detect & log attacks
Psionic PortSentry: detect and respond to
active attacks. Respond: automatically set
kernel filtering rules that add a rule to prohibit
access from the offending system.
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Cons to retaliation? Spoofing.
Firewalls: can be configured to detect port scan
attempts.
Port Scanning
Countermeasures
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Detection
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Windows based
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Genius
BlackIce
Prevention:
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Disable all unnecessary services
Detecting the Operating
System
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The Second objective of scanning to to
determine the operating system.
Tools:
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NMAP (again)
Queso
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Both of these provide Stack Fingerprinting
capabilities
Detecting the Operating
System
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Stack Fingerprinting
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There are many nuances that vary
between one vendor’s IP stack
implementation and another. Probing
these differences can help us begin to
make an educated guess as to the exact
operating system in use. This is known as
stack fingerprinting.
Stack Fingerprinting
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Types of Probes:
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FIN Probe
Bogus Flag Probe
Initial Sequence Number Sampling
“Don’t Fragment Bit” monitoring
TCP intial window size
ACK Value
ICMP error Message Quneching
ICMP message quoting
ICMP error message-echoing integrity
Types of Service (TOS)
Fragmentation Handling
Please see Hacking Exposed (pp55-56) for details of
these probes.
Passive Stack Fingerprinting
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Instead of sending packets to target systems,
attacker passively monitors network traffic to
determine the operating system in use.
Passive Signatures:
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TTL: What does the operating system set as the
time-to-live on the outbound packet?
Window Size: What does the oeprating system set
as the Window Size?
DF: The does operating system set the Don’t
Fragment Bit?
Operating System Detection
Countermeasures
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Detection:
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Port scanning detection tools can be used to
watch for operating system detection
Prevention:
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Not an easy problem. May be possible to change
one of the unique stack fingerprint characteristics,
but may adversely affect the functionality of the
system.
Robust secure proxies or firewalls should be
subject to Internet scans.
ENUMERATION
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Process of Identifying
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Valid user accounts
Poorly protected resource shares
Enumeration Involves
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Difference in level of intrusion:
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Active connection to systems
Directed queries
Types of Information:
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Network resources & share
Users & Groups
Applications & Banners
ENUMERATION
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(Continued)
Windows NT/2000 Enumeration
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Common Internet File System/Server
Message Block (CIFS/SMB)
NetBIOS
Windows NT/2000 Resource Toolkit (NTRK)
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Windows NT Hacking Kit!
Null Sessions
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CIFS/SMB standards include APIs that return rich
information about a machine via TCP port 139-even
to unauthenticated users. First step towards
accessing these APIs is to create a null session.
Create a null session
net use \\129.118.50.37 \IPc$ “” /u:“”
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“Share” – IPC$
Built-in anonymous user /u: “”
Null password “”
Attacker now can access information about:
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Network info, shares, users, groups, registry keys. Etc.
Null Session countermeasures:
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Sessions require access to TCP 139 (and/or
445 on Win 2000)
Filter TCP and UDP ports 139 & 445 at all
perimeter network access devices.
Disable SMB service entirely
Windows NT Service Pack 3 has a facility
named Restrict Anonymous – which prevents
enumeration of sensitive information over null
sessions. This fix is slightly easier to
implement on Windows 2000
NetBIOS Enumeration
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Net view lists domains available on the
network.
X:\>net view /domain
Domain
-------------------------------------ATMO
BA
BA.TTU.EDU
HOME
NTUST
WORKGROUP
The command completed successfully.
NetBIOS Enumeration
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This command list computers in a
particular domain
X:\>net view /domain:atmo
Server Name
Remark
--------------------------------------------------------\\EMPYREAN
\\HABOOB
\\THUNDER
Samba 2.0.4b Server on hailshaft
\\TYPHOON
The command completed successfully.
NetBIOS Enumeration
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Nbtstat: calls up the netBIOS Name Table
from a remote system.
X:\>nbtstat -a 129.118.50.37
Local Area Connection:
Node IpAddress: [129.118.50.38] Scope Id: []
NetBIOS Remote Machine Name Table
Name
Type
Status
--------------------------------------------BAMDC1
<00> UNIQUE
Registered
BAMDC1
<20> UNIQUE
Registered
BA
<00> GROUP
Registered
BA
<1C> GROUP
Registered
BA
<1E> GROUP
Registered
BAMDC1
<03> UNIQUE
Registered
MAC Address = 00-B0-D0-7F-CB-75
Please See Hacking Exposed ch 3, for explanation of these codes.
NetBIOS Enumeration
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nbtStat: Two main drawbacks of nbtstat are that it is
restricted to operating on a single user and its rather
inscrutable output.
nbtScan, a freeware, addresses these issues.
nbtScan can scan a whole range of IP addresses.
Table headers of nbtscan:
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IP Address
NetBIOS Name
Server
User
MAC Address
NetBIOS Enumeration
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Nt/2000 Domain Controllers
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NTRK Tool called nltests identifies the primary and
backup domain controllers in a domain.
Share enumeration tools from RK:
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New view: lists shares on the system
Rmtshare: output similar to net view
Srvcheck: displays shares & authorized users
Srvinfo
NetBIOS Enumeration: 3rd Party
Software
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DumpSec (http://www.somarsoft.com):
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Audits everything for file system permission to services
available on remote system.
Basic user information can be obtained through null session
using DumpSec.
Can be run from Command line, making automation &
scripting easy.
Legion:
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NetBIOS Scanner
GUI
Reveal all available shares.
Tries to connect to shares by using list of user-supplied
passwords.
NetBIOS Enumeration: 3rd Party
Software
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NetBIOS Auditing Tool (NAT):
http://www.hackingexposed.com
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Both command line & graphical interface
Finds & attempts forced entry into shares.
Epdump: shows addresses bound to IP addresses
and port numbers.
Getmac: gets the MAC address & device names for
NICs
Netdom: info about NT domains ona wire, including
domain membership & identities of backup domain
controllers
Netviewx: lists nodes in domains & services they run
NetBIOS Enumeration
Countermeasures
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Deny Access to TCP & UPD 135-139
Block access using a router, firewall, or
other network gatekeepers
Only way to prevent user data from
appearing in NetBIOS name table
dumps is to disable the Alerter and
Messenger service on individual hosts.
NT/2000 SNMP Enumeration
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If the system is running Simple Network
Management Protocol (SNMP) agent
accessible via default community strings like
“public”, enumerating NT users is possible
through snmputil in NTRK.
Snmputil can reveal:
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Running services
Share names
Share paths
Comments on shares
Usernames
Domain names
NT/2000 SNMP Enumeration
Countermeasures
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Countermeasures:
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Remove SNMP agent
If removing is not an option, ensure that it
is properly configured with private
community names (not the default
“public”);
Edit the Registry to permit only approved
access to the SNMP community Name.
NT/2000 Host Enumeration
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Enumerating users via CIFS/SMB
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NTRK tools like usrstat, showgrps, local
and global utilities casn provide more
information about users.
Dumpsec can pull a list of users, groups,
and the NT system’s policies and user
rights.
NT/2000 Host Enumeration
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NTRK Tools such as usrstat, showgrps, local
and global utilities, provide info about users.
Dumpsec:
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Dumpsec and pull a list of users gorups and the
NT systems policies and user rights.
User2sid/sid2user:
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Looks up looks up NT Security Identifiers (SID: a
variable-length numeric value issued to an NT
System at installation) from user name & vice
versa.
NT/2000 Host Enumeration
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Enum:
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A comprehensive enumeration tool.
A Sample of the command line switches:
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-U: Get Userlist
-M: get machine list
_N: get namelist dump
-S: get sharelist
-P: get password policy information
-G: get group and member list
-d: be detailed
Automates the setup and tear down of null
sessions.
NT/2000 Host Enumeration
countermeasures
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Block acess to TCP & UDP ports 135159, and 445.
Disable SMB services or set to
RestrictAnonymous.
Disable file & print sharing for Microsoft
Networks.
Win 2000 Active Directory
Enumeration using Idp

The most fundamental change introduced by Win
20000 is the addition of a lightweight Directory
Access Protocol (LDAP) – based directory service that
Microsoft calls Active Directory(AD). AD is designed
to contain a unified, logical representation of all the
objects relevant to the corporate technology
infrastructure. The Windows 2000 simple LDAP client
called the Active Directory Administration Tool
(ldp.exe) that connects to an AD server and browses
the contents of the directory. Simply pointing ldp at
a Win 2000 domain controller will enumerate all of
the existing users and groups with a simple LDAP
query.
NT/2000 Applications and
Banner Grabbing
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

Connecting to remote applications and
observing the output is called banner
grabbing.
Identifies the software and version running
on the server, which in many cases is enough
to set the vulnerability research process in
motion
Telnet & netcat are two tools for banner
grabbing.
Banner Grabbing
Countermeasures


Inventory mission-critical applications,
and find correct way to disable
presentation of vendor and version in
banners.
Audit regularly with port scans and raw
netcat connects.
The End