First you need to have Angry IP Scanner , Password Revealer and a Web Explorer.
Step 1 : Start Angry IP scanner and goto options > ports. Type in 80 in the first ports text box and click ok.
Then goto options > options ; in the display section select "only open ports" and click ok & save.
Now go to http://www.whatismyip.com . Copy your IP Address (ex: 18.104.22.168) and Paste it in Hostname. Then Press the button next to it (IP^). Then in the IP Range change the IP in the second box(ex:22.214.171.124). Then press on scan.
Step 2: Pick the ip-address of any of them and open up your browser and type it in the Address Bar (ex: http://126.96.36.199/)
A box will popup asking for username and password. Enter the username : admin and password : admin .There is a high chance that you will be able to login with that username and password.
admin-admin is the default username and password that is set while manufacturing the adsl modem devices.
What follows next is the modem administration panel.
Simply search for the "WAN" option and click it. On the next page you will find the username and password of that user. now right-click on the page and click view source. in Mozilla/Opera This frame -> view frame source
Now in the source code search for this : INPUT TYPE="PASSWORD"
and the value field of this input element will have the password
if its not there as in case of D-Link DSL 502T ADSL Routers the search for this
input type="hidden" name="connection0:pppoe:settings/password" value="password" id="uiPostPppoePassword"
and the value field will have the passwordWell each steps take less than 1 minute so getting username passwords wont take even 2 minutes and is easier than sending a mail.
And this exposes the weak security of bsnl broadband users.