[BreachExchange] WannaCry: hackers withdraw £108,000 of bitcoin ransom

[Audrey McNeil]

https://www.theguardian.com/technology/2017/aug/03/
wannacry-hackers-withdraw-108000-pounds-bitcoin-ransom

Over £108,000 in bitcoin paid by victims of the WannaCry ransomware attack,
which crippled parts of the NHS as well as businesses in 150 countries
worldwide, has been withdrawn from the digital wallets the funds were being
held in.

Nearly three months after the ransomware struck computers, locking up data,
demanding ransoms and causing chaos in hospitals and firms including
Spain’s Telefonica and FedEx, a total of £108,953 worth of bitcoin was
withdrawn. The money, presumably moved by the hackers, was taken from three
bitcoin wallets associated with WannaCry, according to tracking firm
Elliptic.

Victims of WannaCry were asked to pay between $300 (£228) and $600 in
ransom with the promise of unlocking the files taken hostage by the
malware, of which there were believed to have been around 230,000 computers
worldwide. While law enforcement advised against paying the ransom, saying
that it would only fund further acts of cyber criminality, victims appear
to have done so in their hundreds to try and get their data back.

Between 24 July and 3 August, more than £18,000 in bitcoin was removed from
the three wallets, with the remainder of the funds taken out in the early
hours of Wednesday morning in seven batches worth between £15,000 and
£21,000 each.

Since the attack, few anticipated that the ransom money would move. Part of
the ransomware program gave the addresses of the digital wallets to victims
and therefore law enforcement, which has been tracking them ever since.
While bitcoin is considered a pseudonymous currency that cannot be tracked
in the same way as traditional currencies, monitoring its movement is
possible due to the way transactions are written into a distributed ledger
called the blockchain.

That makes turning ill-gotten gains into traditional currencies harder to
do anonymously. To do so requires the use of techniques such as a bitcoin
mixer or tumbler, which intentionally confuses the trails of bitcoin
transactions to protect the anonymity of the bitcoin owners.

BTC-e, a major bitcoin exchange accused of laundering $4bn in bitcoin since
it emerged in 2011, was shut down in July after the “internationally sought
criminal mastermind” behind it was arrested in Greece, which will make
anonymously turning the ransom bitcoins into cash even harder.

Elliptic co-founder Tom Robinson told CNBC: “We believe some of these funds
are being converted into Monero, a privacy-focused cryptocurrency.”

The funds may also be used to purchase goods and services directly in
bitcoin on the dark web, adding another layer of difficulty to tracking the
wallets’ owners.

The ransomware attack, which has been linked to North Korea, is thought to
be at least partially politically driven rather than an outright move for
money. As a piece of ransomware designed to extort users, WannaCry was a
victim of its own success hitting large firms and spreading across networks
using holes in Windows XP and Windows 7 to propagate far and wide.

But while ransomware targeting business and institutions causes large
amounts of disruption, such as reducing some NHS hospitals to emergency
care only and forcing them back to pen and paper, businesses are unlikely
to pay the ransom.

Where individual home users may not have backups of their data that can be
easily restored, and therefore are more likely to pay the ransom to try and
get their files back, most businesses will have routine backups and can
restore the majority of files relatively easily once the infection has been
purged.
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