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The telecommunication industry faces a growing threat of theft
of customer services. No telecommunications system can be totally
free from the risk of unauthorized usages. Insuring that your systems
are maintained in a secure manner is therefore a prime responsibility
of each organization. This section provides information on toll
fraud and service theft, and on ways to use the system administration
tools to minimize the possibility of such unauthorized activities
occurring on your system.
The following topics are included:
Toll fraud
Detecting Toll Fraud
Unauthorized system use
Toll Fraud
Toll fraud is one of the most expensive corporate crimes that poses
a major threat to telecommunication systems. Toll frauds can result
in huge phone bills, revenue loss in terms of its operational impact,
additional expenses, service interruptions, and the most important
of them all, loss of customer confidence.
What is Toll Fraud?
Toll Fraud is the unauthorized use of a company's telecommunications
service by an unauthorized party (for example, a person who is not
a corporate employee, an agent, or a subcontractor). It occurs when
people misdirect their own telecommunications charges to another
person or business.
How does Toll Fraud occur?
Toll fraud is possible when your system allows the incoming caller
to make a network connection with another person. It is therefore
important to protect vulnerable areas such as call transfer and
bridging to an outbound call. There are numerous ways in which unauthorized
users can attempt to breach your system security. These include:
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Unauthorized system use. Intruders access
your system and create a mailbox and use the system. Hackers
use personal computers, random number generators, and password
cracking programs to break into customer premises equipment-based
systems. Hackers continuously dial into the PBX or telephone
equipment and probe the system for a weakness that will provide
access to an outside line. Once an outside line is obtained,
long distance calls are made.
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Unauthorized mailbox use. An intruder discovers
how to access a particular mailbox, perhaps by:
- Finding the password on a subscriber's desk or in a wallet
- Trying all the common variations of passwords
- Buying the password from a computer hacker who breached the
system security and logged in as an administrator
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Fraudulent call transfer. An intruder uses
the transfer-to-extension feature by transferring to the first
few digits of a trunk access code.
Warning!
Toll fraud is a theft of long distance service. When
toll fraud occurs, your organization is responsible for the
charges incurred. Call Avaya's Customer Care Center, 1-800-643-2353
for more information on how to prevent toll fraud. |
Voice mail fraud
There are two types of voice mail fraud. The first type, which
is responsible for most of the equipment-related toll fraud loss,
relies on misuse of the call transfer capabilities of voice mail
systems. Once thieves transfer to dial tone, they may dial a Trunk
Access Code (TAC), Feature Access Code, Facility Access Code (FAC),
or an extension number. If the system is not properly secured, thieves
can make fraudulent long distance calls or request a company employee
to transfer them to a long distance number.
The second type of voice mail fraud occurs when a hacker accesses
a mailbox to either take it over or simply access the information
stored within it. In the first situation, a hacker dials either
9 or a TAC that allows the call to be transferred to the outgoing
facilities. In the second situation, a hacker typically hacks the
mail password and changes it along with the greeting. This gives
the hacker access to proprietary corporate information.
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Automated Attendant
Automated attendant systems is a service that connects to the PBX
system to help route calls to the appropriate extension. A menu
of options allows callers to choose a predefined destination, such
as a department, announcement, or an attendant, or a user-defined
destination, such as an extension number. Automated attendant devices
are connected to a port on the main system and provide the necessary
signaling to the switch when a call is being transferred.
Many automated attendant systems are vulnerable to toll fraud and
are easy targets for toll hackers. When hackers connect to an automated
attendant system, they try to find a menu choice (even one that
is unannounced) that leads to an outside facility. Hackers also
may try entering a portion of the toll number they are trying to
call to see if the automated attendant system passes the digits
directly to the switch. To do this, the hacker matches the length
of a valid extension number by dialing only a portion of the long
distance telephone number. For example, if extension numbers are
four digits long, the hacker enters the first four digits of the
long distance number. After the automated attendant sends those
numbers to the switch and disconnects from the call, the hacker
provides the switch with the remaining digits of the number. Many
voice messaging systems incorporate automated attendant features.
Although there are some steps you can take to tighten the security
of the automated attendant itself, additional steps must be taken
on the switch side to reduce the risk of toll fraud.
Before you set up Automated Attendant, ensure that you do the following
to minimize unauthorized usage:
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Never allow a menu choice to transfer to an outgoing trunk
without a specific destination.
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When a digit (1 through 9) is not a menu option, program it
to transfer to an attendant, an announcement, a disconnect,
or other intercept treatment.
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When 8 or 9 are Feature Access Codes for the switch, make sure
the same numbers on the automated attendant menu are either
translated to an extension or, if not a menu option, are programmed
to transfer to an attendant, announcement, disconnect, or other
intercept treatment.
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Restrict call transfers to subscribers when Basic Call Transfer
is used.
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Use outcalling restrictions to prohibit users from obtaining
an external line when they dial an initial digit of an invalid
mailbox number. See the MAS Administration Guide for more information
on outcalling restrictions.
Detecting Toll Fraud
To detect possible hacker activity, users and administrators should
look for the following signals:
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Employees cannot get outside lines.
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Customers have difficulties in getting through to your 800
number. The busy line could even impact local Direct Inward
Dial (DID) lines.
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Unexplained increase in long distance usage.
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Increase in short duration calls.
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Significant increase in internal requests for assistance in
making outbound calls, particularly international ones.
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Nights and weekends have heavy call volumes.
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Sudden increase in wrong numbers.
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Bills show calls made to strange places.
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Attendants report frequent "no one there" or "sorry,
wrong number" calls.
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Switchboard operators complain of frequent hang-ups or touch-tone
sounds when they answer.
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Sudden or unexplained inability to access specific administrative
functions within the system.
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Staff or customer complaints of inability to enter the voice
mail system.
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Simultaneous Direct Inward System Access (DISA) authorization
code use coming from two different places at the same time.
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Unusual increase in usage of customer premises equipment-based
system memory.
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Unexplained changes in system software parameters.
You can use monitoring techniques to review and keep track of various
activities on your system. Modular Messaging provides a Reporting
tool that generates comprehensive reports on subscriber mailbox
port usage, subscriber incoming and outcalling activity, planning
capacity, and tracking system security. You can view each of these
reports for an entire day or for each hour. Reviewing these reports
on a regular basis will help you establish traffic trends. Monitor
your system on a regular basis by using these reporting and monitoring
tools, and take corrective action if you notice any suspicious or
unusual patterns.
In addition, you can use the following measures to reduce the possibilities
of frauds:
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Restrict call transfers to the host PBX by not allowing transfers,
by using Enhanced Call Transfer, or by allowing Transfer to
Subscriber Only.
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When password protection into voice mailboxes is offered, use
the maximum length possible.
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Deactivate unassigned mailboxes and remove unused mailboxes.
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Lock out consecutive unsuccessful attempts to enter a voice
mailbox.
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Establish your password as soon as your voice mail system extension
is assigned. This will ensure that only you have access to your
mailbox.
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Discourage the practice of writing down passwords, storing
them, or sharing them with others. Keep your password in a secure
place and never discard it while it is active.
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Never program passwords on auto dial buttons.
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Contact Avaya for additional measures that you can take to
prevent fraud.
Unauthorized system use
To minimize the risk of unauthorized break-ins to the system, strictly
follow the compliance guidelines for your voice mail (vm) passwords,
system administration (sa) passwords, trusted server passwords,
and use the password aging feature.
Modular Messaging comes with administrative password features and
options that assist you in securing your system. These include:
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Changing default administrator password. When
you first get your system, make sure that you change both the
system administrator, and the voice mail administrator logins
passwords immediately. These logins are used to access the Avaya
Message Storage Server (MSS). Access to the Avaya Messaging
Application Server (MAS) is restricted to Windows Access Control
Lists (ACLs) using the Windows Terminal Services into the MAS.
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Administrator password standards. You must
follow the minimum password standards to comply with the system's
standards.
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Administrator password aging. Use the password
aging feature parameters to enhance the security levels of the
system. This will ensure that administration passwords are changed
at regular intervals. You can also use the password expiration
feature for administrative logins to reduce the danger of unauthorized
access.
See Mailbox Administration for more
information on passwords and mailbox administration.
You can ensure additional security by using the Avaya Access Security
Gateway (ASG) guard which is used to provide secure remote access
to the MSS. See Adjuncts for more
information on ASG.
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