Blockchain & Cryptocurrency , Cryptocurrency Fraud , Fraud Management & Cybercrime

Cryptohack Roundup: Harmony's Post-Exploit Blockchain Rollback

Every week, ISMG rounds up cybersecurity incidents in digital assets. This week, Harmony to roll back blockchain after exploit, Delio CEO sentenced to 15 years in South Korea, an alleged Ponzi promoter deported to the United States, SafePal and Trezor customers' data exposed, and attackers exploited a Mac flaw to mine Monero.

Harmony to Roll Back Blockchain After Massive Token Forgery

Harmony will roll back its blockchain after finding that attackers forged more than 3 trillion One tokens. Validators will restore both parts of Harmony's network to a point before the unauthorized creation of tokens, meaning all transactions recorded afterwards will be discarded.

Harmony considered destroying the forged tokens, blocking affected wallets and moving One to a new token before deciding a rollback was the safest and fairest approach.

The project initially confirmed the exploit on Aug. 12 after a researcher found 4 billion newly created One tokens. A later investigation uncovered 3.01 trillion forged tokens across six transactions involving four attacker wallets. One wallet moved nearly 2.4 trillion One in under two minutes. Harmony said many forged tokens passed through trading platforms and blockchain bridges, making recovery difficult without affecting other users. The attack exploited a flaw that allowed the same valid transaction record to be processed repeatedly (see: Cryptohack Roundup: Harmony, BTCPay Exploits).