yep 100% a scam, either a straight up scam, HYIP, or money laundering scheme. do not touch under any circumstances.
straight up scam.. hey want your coins.
pretending its to be used in a money laundering scam.. why. because they know advertising a money launder/tax evade system means victims wont go to the cops/courts because that involves admitting why they handed money to a stranger(wanting to launder/tax evade)
other scams include
investing into 'chopshop' car theft/resale industry. victims of investment theft wont call the cops.