The last attack attempt was roughly six hours ago; we see no new attacks since then.
(EDIT: this is no longer true; there was a subsequent attack. The last known attack was on May 19th. The text below remains to provide an example for study.)
Here is the last orphaned block seen on the chain, caused by these attacks:
Orphaned chain tip from fork, Block #528953
Source: explorer.bitcoingold.org, timestamp in Eastern Daylight Time, UTC-4.
Here is the block that replaced it, becoming part of the main chain:
Active chain, Block #528953
Source: explorer.bitcoingold.org, timestamp in Eastern Daylight Time, UTC-4.
No newer orphaned blocks sitting on a chain tip have been seen since then. Any new attack would create a new orphaned chain tip.
Technical note: Chain information is available from any Full Node, using the getchaintips command:
getchaintips
[{
“height”: 528980,
“hash”: “000000001cf5dbb022414111af2f9b4636a08489743b27b4ad56a8ab45bb8822”,
“branchlen”: 0,
“status”: “active”
},
{
“height”: 528953,
“hash”: “0000000024cc17971de3cf0b03f527562093cd5e10ee26562376b1b40df65776”,
“branchlen”: 2,
“status”: “valid-fork”
}, …
Note that orphaned blocks can be explored in explorer.bitcoingold.org by entering the block hash - searching on the block number will always return the mainchain block, not the orphaned block, but entering the actual hash will show a block that was orphaned.