[BreachExchange] Lazarus Hacking Groups Behind the Targeted VHD Ransomware Attacks

[Destry Winant]

https://gbhackers.com/vhd-ransomware/

Lazarus hacker group is known for its attack on Sony Pictures in 2014,
the group is financially motivated and know to be active since 2009.

The Lazarus Group believed to be operated by the North Korean
government, the group is designated as an advanced persistent threat
due to intended nature, threat, and a wide array of methods.

Starting from the year 2020, targeted ransomware attacks are on the
rise, researchers discovered the recent ransomware strain, called VHD,
associated with an unfamiliar source.

APT Tactics with VHD Ransomware Attacks

Researchers observed a new ransomware campaign that uses APT groups
spreading techniques deployed only in a limited number of instances.

Attackers use piggyback methods to spread the infection into the
victim’s network and once they gain understanding about the target’s
finances and IT structures they process the encryption.

Kaspersky researchers observed an incident in Europe that features the
new ransomware family VHD and it uses written in C++ distributed APT
group spreading technique.

The ransomware has nothing special, like other ransomware it “crawls
all connected disks to encrypt files and delete any folder called
System Volume Information. Also, it blocks process locking important
files.”

The files are encrypted in the combination of AES-256 in ECB mode and
RSA-2048 and it also includes a mechanism to resume ransomware if
interested.

The ransomware also includes a spreading utility that propagates
ransomware inside the network, the spreading utility contains a list
of admin credentials that used to brute-force SMB service on every
machine.

“Whenever a successful connection was made, a network share was
mounted, and the VHD ransomware was copied and executed through WMI
calls. This stood out to us as an uncharacteristic technique for
cybercrime groups; instead, it reminded us of the APT campaigns Sony
SPE, Shamoon and OlympicDestroyer, three previous wipers with worming
capabilities.”

Researchers felt that attack did “not fit the usual modus operandi of
known big-game hunting groups, also limited public samples found.”

In another incident, the attackers exploit a vulnerable VPN gateway
that allows attackers to admin access and they deploy a backdoor to
take over the Active Directory server and to deploy the ransomware.

“The data we have at our disposal tends to indicate that the VHD
ransomware is not a commercial off-the-shelf product; and as far as we
know, the Lazarus group is the sole owner of the MATA framework.”

IoC

SHA-256

6D12547772B57A6DA2B25D2188451983
D0806C9D8BCEA0BD47D80FA004744D7D
DD00A8610BB84B54E99AE8099DB1FC20
CCC6026ACF7EADADA9ADACCAB70CA4D6
EFD4A87E7C5DCBB64B7313A13B4B1012

The ransomware attacks now become an easy and malicious way of robbing
individuals and company’s can cost billions of dollars not to mention
the privacy and safety implications.