1,100 XRP Transfer I Didn't Make

[pedTrader]

To make a long story short I joined Ripple when it first started and got 1,100 XRP.  I forgot about it for years and came back to my account to find that ripple not longer hosted the wallet and it had to be transferred to gatehub.  Luckily I backed up, so I loaded my wallet into gate hub and found a 1,100 XRP transaction I did not make had been made to a Poloniex account only one month ago!  Is this part of the account migration process or am I completely out of luck and those xrp are lost in the sands of time?  If it is part of the process how can I get my xrp back?

Thanks

Link to transaction: https://xrpcharts.ripple.com/#/transactions/142501F0BF90DC1C9CEF74B1B6B9BB00CF43C0B9B4D2E74E45175BA47F2649E0