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TECHNOLOGY






                                                                                                                                 connected by hubs (WIFI). Active   on one point — about one-third   correct host is also ensured in such
                                                                                                                                 sniffing launches Address Resolu-  smartphone users have problems   cases.
                                                                                                                                 tion Protocol (ARP) spoofing; traf-  with insecure communication or   In a normal situation, a host
                                                                                                                                 fic flooding attack against a switch   WIFI. In many mobile Applications,   gets the data intended for it. It will
                                                                                                                                 in order to capture traffic. Passive   data storage is not secure; authori-  never receive data intended for
                                                                                                                                 sniffing is hard to detect. The active   sation controls are not secure too.  another host. However, the sniffer
                                                                                                                                 one is detectable.              Then what happen? In normal   can receive data not intended for it.
                                                                                                                                   In cases of hubs or wireless me-  cases, any system will read and    And here Address Resolution Pro-
                                                                                                                                 dia (WIFI), all hosts on the network   respond to the traffic sent directly to  tocol (ARP) plays a major role while
                                                                                                                                 can see all traffic; it makes the life   the MAC address. However, chang-  data travel over the network.
                                                                                                                                 of sniffer much easier. A passive   ing the Network Interface Card
                                                                                                                                 sniffer can capture traffic going to   (NIC) to promiscuous mode changes  How does ARP work?
                                                                                                                                 and from all hosts connected via the  the game altogether.  To reach one host, another host
                                                                                                                                 wireless media.                 Many hacking tools change the   needs the MAC address; although
                                                                                                                                   Almost  every  smartphone,   system-dependent NIC to promis-  IP address is the first necessity. ARP
                                                                                                                                 somehow or other uses WIFI. My   cuous mode. In promiscuous mode,  translates the IP address to the MAC
                                                                                                                                 mother uses it too and probably   NIC reads all traffic and sends it to   address to help the host to get to
                                                                                                                                 your mothers. They simply hate   the sniffer. Many hacking tools also   the proper address. If the host has
                                                                                                                                 the idea of using a desktop or lap-  incorporate specially designed pro-  a past conversation record with
                                                                                                                                 top connected to Internet through                           another host, it first searches its
                                                                                                                                 LAN and cable. They seem horrible                           ARP cache to find out the MAC
                                                                                                                                 to them.                       When mobile apps             address. If it has not done that, it
                                                                                                                                                                                             asks for the IP address first through
                                                                                                                                                                use third-party
                 Mobile banking kicks                                                                                            However, LAN connections are   Application                  the ARP broadcast.
                                                                                                                                 always more secure than WIFI.
                                                                                                                                                                                               What attacker does is apparently
                                                                                                                                 Why? The switch works in a differ-
                                                                                                                                                                                             simple. It sends a fake or spoofed
                                                                                                                                                                Programming
                                                                                                                                                                                             ARP message to the Ethernet LAN.
                                                                                                                                 ent way. It sends data according to
                 off in style!                                                                                                   the MAC address (the hardware or   Interface to             These frames contain false MAC ad-
                                                                                                                                                                                             dresses that are enough to confuse
                                                                                                                                 physical address of the computer). It
                                                                                                                                                                communicate
                                                                                                                                 is much organized and it maintains
                                                                                                                                                                                             the network devices like switches. It
                                                                                                                                 a MAC table of all systems and port
                                                                                                                                                                                             ternatively, it can be sent to the un-
                                                                                                                                 numbers to which it is connected.   over the network,       allows the packets to be sniffed. Al-
                                                                                                                                 For this reason, the switch is always   it is always scarier   reachable addresses that you know
                 About one-third of the                 ecently, I have been get-  researchers find security flaws in            safer than hubs or WIFI. However,   as one has no           as denial of service (DoS) attack. We
                 smartphone users,                      ting a little bit of tremu-  mobile applications almost every            it is not totally foolproof. Using   control over it        call it ARP spoofing or poisoning.
                                                        lous. I can remember
                                                                                                                                                                                               Search common vulnerabilities
                                                                                                                                 span port or port mirroring may
                                                                             other day.
                 especially in mid 50s have             the  excitement  when   My mother does not understand                    enable all data to be duplicated to                         of mobile applications over the
                 problems with insecure        R my mother had first dis-    host-to-host network communi-                       another port. Protocols are always   miscuous mode driver that facili-  Internet.  You  will  find  tons  of
                                                                                                                                                                                             reports. When mobile Applications
                                               covered the Mobile Banking App on  cation. She does not care about
                                                                                                                                 susceptible to sniffer if they are not
                 communication or WIFI.        her smartphone. It was a great relief  how data travel over a network,            encrypted. Unfortunately, most of   tates the sniffing process.  use third-party Application Pro-
                 Options such as data          that she did not have to go to the   she hardly cares about the old OSI           the smartphone users do not use                             gramming Interface (API) to com-
                 storage or authorisation      bank anymore. She used to get stuck  model which has seven layers of              proper encryption or use broken   Dissecting technical details  municate over the network, it is
                                                                                                                                 encryption. Using a sniffer you can
                                                                             data communication. She cares a fig
                                                                                                                                                               When data travels over the net-
                                                                                                                                                                                             always scarier. You have no controls
                                               in the serpentine queue to with-
                 controls are not secured in   draw money. That was a headache.   about the sniffer tools easily avail-          easily capture protocols such as   work, the header information is   over those APIs. You never know
                 many mobile banking           Now, she transfers money, buys   able for obtaining important infor-              HTTP, POP3, Simple Network Man-  added to the beginning of the data.   what types of vulnerabilities they
                                                                                                                                                                                             are adding to your smartphone. So
                                                                                                                                                               There are two types of header data
                                                                             mation sent from a target system.
                                                                                                                                 agement Protocol (SNMP), and FTP.
                                               anything or make payments in the
                 applications. Question is     grocery store in the blink of an eye.  However, we, professional pen-             Username and passwords can also   — an IP header contains source and  the risk is high.
                 whether Mobile Banking          It is super cool and super hot at   etration testers really care a damn         be extracted from sniffing.   destination IP addresses and the   I have convinced my mother to
                                                                                                                                   Once I had tried to explain these
                 is really safe?               the same time. And, things started   and have probably become con-                little facts to my mother and she   MAC header contains the source   keep a minimum amount of balance
                                                                                                                                                                                             in her savings account. What can I
                                                                             cerned about these little technical
                                                                                                                                                               and destination MAC addresses. IP
                                               to get alarming. Am I a Goliath frog
                 SANJIB SINHA writes           belonging to the Jurassic age? Am   facts.                                        stood up, anger rising, and I stopped  addresses are necessary for rout-  do? She finds mobile banking very
                                               I blind as a bat, not able to see the   Two types of sniffing are there –         quickly. I sensed she could throw   ing traffic to the correct IP network.  easy. It’s actually easy and surpris-
                                               headway in mobile technology? Or   passive and active. Passive sniffer            the book she was reading. But, be-  MAC addresses assure one thing —   ingly scary at the same time!
                                               as an ethical hacker, I have become   listens to and captures traffic. It         lieve me, this threat is looming up   the data is sent to the correct des-
                                               fidgety and uneasy just because the   is especially useful in a network           out of the dark. Researchers agree   tination network. Delivery to the   LETTERS@TEHELKA.COM
                                      TEHELKA / 30 NOVEMBER 2018  44  WWW.TEHELKA.COM                                                                 TEHELKA / 30 NOVEMBER 2018  45  WWW.TEHELKA.COM
   44-45 Sanjib Sinha.indd   2                                                                    11/16/2018   10:38:52 AM  44-45 Sanjib Sinha.indd   3                                                           11/16/2018   10:38:58 AM
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