Final message of Cryptopia:
27th November - IFC suffered a 51% attack to its' network. This resulted in the loss of coins in Cryptopia users IFC addresses. Unfortunately Cryptopia is unable to regulate a coins network and IFC will be de-listed. Delist date: 27/12/2017
I cannot see any major reversals in the debug log, or in my pool system (which reports when the chain reorganises). A 51% attack would show a disconnect of several blocks and/or a connect of several blocks. A disconnect of 1 then reconnect of 2 is simply two miners finding a block at the same time and the network sorting out the (tiny) fork. I wonder if 27th was supposed to refer to the date of the attack, or it's when they posted the announcement, and it happened much earlier. No sign of a 51% with the data I have.
11/25/17 06:03:55 REORGANIZE: Disconnect 1 blocks; 00000003b46fccdc01f9..00000000646f07fd2cab
11/25/17 06:03:55 REORGANIZE: Connect 2 blocks; 00000003b46fccdc01f9..0000000217feed30b3d5
11/25/17 08:02:10 REORGANIZE: Disconnect 1 blocks; 00000000680b9fc488dc..000000018ce0deb68c53
11/25/17 08:02:10 REORGANIZE: Connect 2 blocks; 00000000680b9fc488dc..000000012ee1febd1a61
11/25/17 09:04:41 REORGANIZE: Disconnect 1 blocks; 000000021ca5b094b5f8..000000024d511163ac4e
11/25/17 09:04:41 REORGANIZE: Connect 2 blocks; 000000021ca5b094b5f8..000000001a591b6a76c5
11/25/17 11:04:28 REORGANIZE: Disconnect 1 blocks; 000000014a0d2a79b275..0000000111543405b92d
11/25/17 11:04:28 REORGANIZE: Connect 2 blocks; 000000014a0d2a79b275..000000015903c7ccf578
11/25/17 12:49:58 REORGANIZE: Disconnect 1 blocks; 000000013dcaef9306ac..00000000e7ed090b4a75
11/25/17 12:49:58 REORGANIZE: Connect 2 blocks; 000000013dcaef9306ac..00000000f9ed154f9776
11/25/17 15:17:19 REORGANIZE: Disconnect 1 blocks; 00000000b6f9477edef4..000000004603947a45e8
11/25/17 15:17:19 REORGANIZE: Connect 2 blocks; 00000000b6f9477edef4..00000000908db9a25fb6
11/25/17 17:48:11 REORGANIZE: Disconnect 1 blocks; 000000002edaf98e29b2..000000005395b4486a8b
11/25/17 17:48:11 REORGANIZE: Connect 2 blocks; 000000002edaf98e29b2..000000002db64552a683
11/25/17 19:27:35 REORGANIZE: Disconnect 1 blocks; 0000000004d901a4b7d3..000000005c6c0294ffa4
11/25/17 19:27:35 REORGANIZE: Connect 2 blocks; 0000000004d901a4b7d3..000000002504b1ac4f35
11/25/17 23:49:10 REORGANIZE: Disconnect 1 blocks; 00000000156b22c1ad87..000000000635738914be
11/25/17 23:49:10 REORGANIZE: Connect 2 blocks; 00000000156b22c1ad87..00000000247e2a6dc012
11/26/17 00:44:47 REORGANIZE: Disconnect 1 blocks; 000000001b0dccf4a7b2..000000000e811bbaeb44
11/26/17 00:44:47 REORGANIZE: Connect 2 blocks; 000000001b0dccf4a7b2..00000000349342630749
11/26/17 05:17:46 REORGANIZE: Disconnect 1 blocks; 0000000041d510d9df49..00000000096c57d49454
11/26/17 05:17:46 REORGANIZE: Connect 2 blocks; 0000000041d510d9df49..000000002658c24584bd
11/26/17 05:47:54 REORGANIZE: Disconnect 1 blocks; 000000001a280b32fcd0..000000002ea1d43ebbdb
11/26/17 05:47:54 REORGANIZE: Connect 2 blocks; 000000001a280b32fcd0..000000001ccda5514c95
11/26/17 07:17:14 REORGANIZE: Disconnect 1 blocks; 0000000020622552498a..000000001d2402c016b6
11/26/17 07:17:14 REORGANIZE: Connect 2 blocks; 0000000020622552498a..000000002a4deff4953c
11/26/17 10:11:37 REORGANIZE: Disconnect 1 blocks; 00000000145e9c1031dd..00000000088bde0eb742
11/26/17 10:11:37 REORGANIZE: Connect 2 blocks; 00000000145e9c1031dd..00000000014a76ca476a
11/26/17 10:26:29 REORGANIZE: Disconnect 1 blocks; 0000000017ed01282a30..000000000dc7a6d49635
11/26/17 10:26:29 REORGANIZE: Connect 2 blocks; 0000000017ed01282a30..000000000099088059dd
11/26/17 11:31:10 REORGANIZE: Disconnect 1 blocks; 000000000c7a65b83005..000000000fbe3098b98e
11/26/17 11:31:10 REORGANIZE: Connect 2 blocks; 000000000c7a65b83005..0000000021552cb6735a
11/26/17 11:57:37 REORGANIZE: Disconnect 1 blocks; 00000000239f7fe80a94..000000003611e8d5c5d7
11/26/17 11:57:37 REORGANIZE: Connect 2 blocks; 00000000239f7fe80a94..0000000010097050aa5c
11/26/17 12:01:53 REORGANIZE: Disconnect 1 blocks; 00000000289c3226cf37..0000000048390c1b6fb0
11/26/17 12:01:53 REORGANIZE: Connect 2 blocks; 00000000289c3226cf37..0000000040e1486dfa72
11/26/17 16:05:20 REORGANIZE: Disconnect 1 blocks; 000000003af55da54c6a..000000002233a143bdee
11/26/17 16:05:20 REORGANIZE: Connect 2 blocks; 000000003af55da54c6a..000000000b48dfb9ef6b
11/26/17 16:08:34 REORGANIZE: Disconnect 1 blocks; 0000000006cbc6620db6..000000000507f6970694
11/26/17 16:08:34 REORGANIZE: Connect 2 blocks; 0000000006cbc6620db6..000000002afc626e762a
11/27/17 04:06:51 REORGANIZE: Disconnect 1 blocks; 00000000361873edd200..0000000009282864c84d
11/27/17 04:06:51 REORGANIZE: Connect 2 blocks; 00000000361873edd200..000000001f46073fdc33
11/27/17 09:41:44 REORGANIZE: Disconnect 1 blocks; 000000004c8d999a54b6..000000005bb747a27061
11/27/17 09:41:44 REORGANIZE: Connect 2 blocks; 000000004c8d999a54b6..00000000a0b1d73d4494
11/27/17 20:05:26 REORGANIZE: Disconnect 1 blocks; 00000000298467288bf8..00000000365b26a95ab3
11/27/17 20:05:26 REORGANIZE: Connect 2 blocks; 00000000298467288bf8..00000000196caa552bf2
11/27/17 21:06:40 REORGANIZE: Disconnect 1 blocks; 000000000dde627ba407..00000000166724e497ff
11/27/17 21:06:40 REORGANIZE: Connect 2 blocks; 000000000dde627ba407..00000000202fef9840d1
I think that whatever happened was on the 17th of August. Check their transactions for that day....