diff --git a/attack/attack.go b/attack/attack.go
index 778390d2b..199289efc 100644
--- a/attack/attack.go
+++ b/attack/attack.go
@@ -4,6 +4,7 @@ import (
 	"harmony-benchmark/log"
 	"math/rand"
 	"os"
+	"sync"
 	"time"
 )
 
@@ -16,19 +17,29 @@ const (
 
 // AttackModel contains different models of attacking.
 type Attack struct {
-	log log.Logger // Log utility
+	AttackEnabled bool
+	log           log.Logger // Log utility
 }
 
-func New(log log.Logger) *Attack {
-	attackModel := Attack{}
-	// Logger
-	attackModel.log = log
-	return &attackModel
+var attack *Attack
+var once sync.Once
+
+// GetAttackModel returns attack model by using singleton pattern.
+func GetAttackModel() *Attack {
+	once.Do(func() {
+		attack = &Attack{}
+		attack.AttackEnabled = AttackEnabled
+	})
+	return attack
+}
+
+func (attack *Attack) SetLogger(log log.Logger) {
+	attack.log = log
 }
 
 // Run runs all attack models in goroutine mode.
 func (attack *Attack) Run() {
-	if !AttackEnabled {
+	if !attack.AttackEnabled {
 		return
 	}
 	// Adding attack model here.
@@ -49,8 +60,8 @@ func (attack *Attack) NodeKilledByItSelf() {
 	}
 }
 
-func DelayResponse() {
-	if !AttackEnabled {
+func (attack *Attack) DelayResponse() {
+	if !attack.AttackEnabled {
 		return
 	}
 	if rand.Intn(HitRate) == 0 {
diff --git a/benchmark.go b/benchmark.go
index 4c2548b61..bd201b450 100644
--- a/benchmark.go
+++ b/benchmark.go
@@ -15,6 +15,10 @@ import (
 	"time"
 )
 
+const (
+	AttackProbability = 20
+)
+
 func getShardId(myIp, myPort string, config *[][]string) string {
 	for _, node := range *config {
 		ip, port, shardId := node[0], node[1], node[3]
@@ -74,16 +78,32 @@ func readConfigFile(configFile string) [][]string {
 	return result
 }
 
+func attackDetermination(attackedMode int) bool {
+	switch attackedMode {
+	case 0:
+		return false
+	case 1:
+		return true
+	case 2:
+		return rand.Intn(100) < AttackProbability
+	}
+	return false
+}
+
 func main() {
 	ip := flag.String("ip", "127.0.0.1", "IP of the node")
 	port := flag.String("port", "9000", "port of the node.")
 	configFile := flag.String("config_file", "config.txt", "file containing all ip addresses")
 	logFolder := flag.String("log_folder", "latest", "the folder collecting the logs of this execution")
+	attackedMode := flag.Int("attacked_mode", 0, "0 means not attacked, 1 means attacked, 2 means being open to be selected as attacked")
 	flag.Parse()
 
 	// Set up randomization seed.
 	rand.Seed(int64(time.Now().Nanosecond()))
 
+	// Attack determination.
+	attack.GetAttackModel().AttackEnabled = attackDetermination(*attackedMode)
+
 	config := readConfigFile(*configFile)
 	shardId := getShardId(*ip, *port, &config)
 	peers := getPeers(*ip, *port, shardId, &config)
@@ -101,7 +121,8 @@ func main() {
 	consensus := consensus.NewConsensus(*ip, *port, shardId, peers, leader)
 
 	node := node.NewNode(&consensus)
-	attack := attack.New(consensus.Log)
+	// Set logger to attack model.
+	attack.GetAttackModel().SetLogger(consensus.Log)
 
 	clientPeer := getClientPeer(&config)
 	// If there is a client configured in the node list.
@@ -129,7 +150,7 @@ func main() {
 
 	// TODO(minhdoan): Enable it later after done attacking.
 	// Run attack.
-	attack.Run()
+	attack.GetAttackModel().Run()
 
 	node.StartServer(*port)
 }
diff --git a/p2p/peer.go b/p2p/peer.go
index eb0375568..3e32a11e7 100644
--- a/p2p/peer.go
+++ b/p2p/peer.go
@@ -80,7 +80,7 @@ func sendWithSocketClient(ip, port string, message []byte) (res string) {
 // Send a message to another node with given port.
 func send(ip, port string, message []byte) (returnMessage string) {
 	// Add attack code here.
-	attack.DelayResponse()
+	attack.GetAttackModel().DelayResponse()
 
 	sendWithSocketClient(ip, port, message)
 	return