Majority who get attacked are Pendu (village Indians), who work odd/late shifts which pays them more money. As they are not fit to live and acclimatize to the life of metropolitans such as Delhi or Mumbai, due to which, they become sudden misfits when they are exposed to culture of cities 10 times more advanced (e.g Melbourn). These people who have sold their village lands to take up courses such as cookery, hotel management etc and other short-term schemes are there only to make money and get PR, if not then work illegally. They lack basic city manners, curtsey, English (language), physical cleanliness and are rude. Some of them live life worst than a Junkie minus Pot. They are one of the most dirtiest lot and usually gets attacked.
Above all the people who attack are not always white, there is a major Lebanese and Black Gang problem in cities such as Sydney and Melbourne, these Pendus cannot differentiate between an Aussie and a Wog? For them every white is an Aussie, and majority of the attacks take place with the motive of robbing and shabby appearance of this particular lot.
Ask Indians who live in class and have friends from all communities (are not doing double shifts like these pendus), they live in good places not the shabby areas away from the city due to cheaper accommodations; such Indians feel more safe than anyone else. These semi-literate village people invite such incidents on themselves and are afraid to fight back due to PR and language issues.
And as per ganging up and fighting back, I know many Indians who have trashed not just Lebanese but even Aussies, my brother's friend has a police case on him for beating up two racist white boys single handedly, the only difference was that he had confidence and was from a good family, moreover, taking crap was not his cup of tea, he knew the law and got his way out because he was well educated and from Delhi. Indians from well educated backgrounds and good families may face some racial slurs but never get attacked by gangs, as they know the no-go Lebanese/Black zones where even Aussies don't enter.
In the end, I would say even Aussies get attacked and killed, crime has increased manifolds in Australia due to immigration from asylum seeking nations and things don't look very rosy for law and order situation. People from India who are illiterate, under confident and lack proper exposure will always face trouble in foreign lands. There has been a huge IELTS/Toffel scam (to get admissions) which has been unearthed, wherein all these Pendu people scored high score in English exams, when in reality, they could not speak/read/write a sentence of English. Aussies have strengthen their Visa policy and have understood the issue of undeserving people entering Australia, I am sure things will start improving when student visas are issued to deserving students and not to the people who have a sole aim to drive cabs (after immigration).