North Korean hackers are getting increasingly dangerous

An illustration of a fingerprint set in front of a series of coding numbers
Illustration: Leon Neal/Getty Images

North Korea's fingerprints have appeared over the past 18 months on an increasing number of surprisingly sophisticated cyber-attacks, The Wall Street Journal's Timothy W. Martin writes from Seoul.

Why it matters: "As North Korea prepares for possible negotiations with Washington aimed at freezing its nuclear program, its hacking capabilities could help it generate money to compensate for economic sanctions or to threaten foreign financial institutions."