Bankinfosecurity.com reported that to “steal cryptocurrency, attackers continue to leverage malware, phishing attacks and fake advertising campaigns.”  The June 12, 2018 article entitled “Cryptocurrency Theft: $1.1 Billion Stolen in Last 6 Months” included the comments from endpoint security firm Carbon Black “which analyzes cryptocurrency attacks that have been seen over the past six months”:

There are currently an estimated 12,000 dark web marketplaces selling approximately 34,000 offerings related to crypto theft,…which says the tools cost anywhere from $1 to $1,000, with an average cost of $224.

….also identified a sweet spot in malware pricing for cryptocurrency-related attacks at around $10.

So maybe cryptocurrencies are not all that safe from cyber criminals!