How to Implement Network Insider Threat in NS2

To implement the Network Insider Threat in NS2 required us to simulate an environment in which the legalized user (insider) purposely or accidentally makes harm to the network, either by breaching information, interrupting services or manipulating traffic. In NS2, we can mimic this by generating mischievous node or agents that perform actions like packet injection, alteration or dropping.

The below approach will show how you can implement a basic network insider threat scenario in NS2:

Step-by-Step Implementation:

  1. Set Up NS2

Make sure NS2 is installed and executing on your system. If not, install it using the given command:

sudo apt-get install ns2

  1. Define the Network Topology

Start by configuring a simple network topology in NS2. State the nodes, links, and communication paths by using a Tcl script.

Example:

set ns [new Simulator]

set tracefile [open insider_threat.tr w]

$ns trace-all $tracefile

# Create nodes

set n1 [$ns node]    ;# Normal node (Sender)

set n2 [$ns node]    ;# Insider (Malicious node)

set n3 [$ns node]    ;# Normal node (Receiver)

# Create links between nodes

$ns duplex-link $n1 $n2 1Mb 10ms DropTail

$ns duplex-link $n2 $n3 1Mb 10ms DropTail

# Set up traffic from n1 to n3 (through n2)

  1. Simulate Normal Traffic

Imitate normal traffic amongst two nodes, which will be intercepted by the insider node (n2).

Example of designing normal traffic (using UDP and CBR):

# Set up normal UDP traffic between n1 and n3

set udp1 [new Agent/UDP]

set null1 [new Agent/Null]

$ns attach-agent $n1 $udp1

$ns attach-agent $n3 $null1

$ns connect $udp1 $null1

# Create a CBR traffic generator attached to UDP

set cbr1 [new Application/Traffic/CBR]

$cbr1 set packetSize_ 512

$cbr1 set rate_ 1Mb

$cbr1 attach-agent $udp1

  1. Introduce the Insider Threat (Malicious Node)

In this step, you simulate the activities of the mischievous insider node (n2). The insider can exhibit various kinds of malicious actions, include:

  • Packet Dropping: The insider drops particular packets, distracting communication.
  • Packet Modification: The insider alters packet contents.
  • Packet Injection: The insider inserts additional traffic into the network, building congestion or confusion.

(A) Simulate Packet Dropping

To mimic packet dropping, the malicious node will receive packets and decide whether to drop or dispatch them.

# Function to simulate malicious packet dropping

proc drop_packet {pkt} {

set decision [expr {rand() < 0.5}] ;# 50% chance of dropping the packet

if { $decision == 1 } {

puts “Malicious node dropping packet”

return 0 ;# Drop the packet

} else {

puts “Malicious node forwarding packet”

return 1 ;# Forward the packet

}

}

# Set up a UDP agent for n2 (malicious node)

set udp2 [new Agent/UDP]

set null2 [new Agent/Null]

$ns attach-agent $n2 $udp2

$ns attach-agent $n3 $null2

$ns connect $udp2 $null2

# Simulate traffic inspection by the malicious insider

$ns at 1.0 “if {[drop_packet $udp1]} { $ns connect $udp1 $udp2 }”

(B) Simulate Packet Modification

In this case, the insider alters the content of the packet before forwarding it.

# Function to simulate packet modification

proc modify_packet {pkt} {

puts “Malicious node modifying packet”

return “Modified_”$pkt

}

# Modify packet at n2 before forwarding to n3

$ns at 1.5 “set mod_packet [modify_packet $udp1]; $ns connect $udp2 $mod_packet”

(C) Simulate Packet Injection

The insider node adds extra traffic to flood the network.

# Set up additional UDP traffic from n2 to n3 (simulating packet injection)

set udp_inject [new Agent/UDP]

set cbr_inject [new Application/Traffic/CBR]

$cbr_inject set packetSize_ 512

$cbr_inject set rate_ 2Mb

$cbr_inject attach-agent $udp_inject

# Inject additional traffic from malicious node n2

$ns attach-agent $n2 $udp_inject

$ns connect $udp_inject $null1

$ns at 2.0 “$cbr_inject start”

  1. Simulate Insider Detection and Mitigation

You can replicate detection and mitigation techniques in NS2 like monitoring traffic actions (such as using logging or counters to spot unusual traffic patterns) and isolating the insider node.

Example:

# Function to detect malicious activity based on packet drop rate

proc detect_malicious_activity {drops threshold} {

if { $drops > $threshold } {

puts “Malicious activity detected: Isolating node”

return 1 ;# Trigger mitigation (e.g., isolate the node)

} else {

return 0 ;# No malicious activity detected

}

}

# Count dropped packets (simple counter for demo purposes)

set drop_count 0

set threshold 10

$ns at 3.0 “if {[detect_malicious_activity $drop_count $threshold]} { $ns detach-agent $n2 }”

  1. Run the Simulation

Once your Tcl script is ready, executes the NS2 simulation using:

ns your_script.tcl

  1. Analyze Results

After the simulation is done, evaluate the produced trace file (insider_threat.tr) for any malicious activity:

  • Look for dropped, adjusted, or inserted packets.
  • Use visualization tools like NAM (Network Animator) to envision the insider’s actions.
  1. Extend the Simulation

You can extend this scenario by:

  • Replicating various kinds of insider threats includes data exfiltration, network blocked attacks, or colluding insiders.
  • Executing more sophisticated detection algorithms that observe network behavior for signs of an insider threat.
  • Simulating mitigation methods like isolating the insider node from the network or throttling traffic to prevent damage.

In this procedure, we aggregated the essential information delivered as a guide to implement a network insider threat in ns2 simulation and how to include their latest features into it. If needed, we will present details regarding insider threats or preventing mechanisms through another approach. To successfully implement the Network Insider Threat in NS2, we encourage you to share your research details with us. We are here to provide you with the best research ideas to support your work