Strange. It looks like Base64 but
echo vvBCn_XFxQQvHBR-lX1BSw== | base64 --decode
Throws an invalid input error.
and
hURL -b "vvBCn_XFxQQvHBR-lX1BSw=="
outputs
Original string :: vvBCn_XFxQQvHBR-lX1BSw==
base64 DEcoded string :: ��B�qqA
�W��
I''m stumped