Perhaps it is not an overstatement to say that influences of Brhamism on Asian religions and magic practices are great. Not only many Chinese and Buddhist deities and mantras are influenced by Hindu gods and goddesses; the magic and herbal practices in Southeast Asia are almost of all Hindu origin. This is perhaps the remnant influence of Sri Vijaya Empire.
The Thai magic is mainly influenced by Buddhism and Brahmism, but I see the influence on Brahmism is more than that the Buddhism as many gods and goddesses are of Hindu origin: the 108 Thai hermits and 8 major Lersi, the Kurba Archan, Kali, Laksmi, Siva, Hanuman etc. Well, that is the obvious side.
On the not so obvious sides, Thai black magicians like to use Ayurvedic herbs, corpses, bones, hairs and cremation ashes for magic workings, which coincidentally, resemble the use of corpses in Ucchusama Sutra and the like Left-Hand Tantric rituals.
If we move further south to Peninsula Malaysia, the once popular Hantu Raya or familiar spirit conjuration method resembles the Hindu and Buddhist tantric methods of calling for female Yaksa or Kali for assistance. The accompanied method of making Santau (poisons) matches that of using ingredients such as: poisons, blood, ghee and herbs in Ucchusama Sutra.
In Java, the practice of Asma Sungei Rajah (ASR) or the Ilmu Saefi requires a practitioner to stand in waist depth to recite mantra at night; this is also stated in Ucchusama and Avalokitesvara Sutras. In both of the sutra that if one wishes to command dragons, then he should go into the water and recite mantra. I think perhaps the ASR or Saefi also invoke dragon power as it is said that the energy of both of ASR and Saefi is ‘hot’. Needless to say that the Balinese magic is predominantly Hindu as the practice of Leak is a typical example of Hindu influence. Other deities are Barong, Garuda, and Naga etc.
It is even stated in Ucchusama Sutra that there is a ritual to make a sword stand by reciting mantra to accomplish Siddhi; which is similar in making a Malay Keris stands. So, the influence of Hindu is pretty obvious. Of course, some people believe that the Keris has a ‘kodam’ (spirit) but some think that it is the balancing of the keris that enables the keris to balance itself.
If I would draw a line, I would think that Hindu influences halted at the border of Vietnam as the Vietnamese magic does not resembles Hinduism at all. Vietnamese magic is influenced by Taoism and Chinese Mahayana Buddhism. Perhaps, the Sri Vijaya influence was not able to penetrate the Indochina in the past.