Categories: Cyber warfareMalwareSecurity

Multiplatform Wiper widespread in attacks against South Korea

Recently South Korea has been hit by powerful cyber attack malware based, network provided by LG UPlus Corp was hacked by a group calling itself the “Whois Team”. The attack targeted also media and banking of the country, television networks YTN, MBC and KBS and Shinhan Bank and NongHyup Bank, two major banks of the country, suffered serious outage. Fortunately according South Korea’s representative none of critical infrastructures of the country was interested by the attacks.

All principal security firms are investigating on the event analyzing the malicious code used for the attacks that revealed the capability to erase data also on Linux machines. The source code of the Windows malware used by attackers presented an unexpected surprise, it was in fact equipped with a module able to work on Linux systems erasing the disks.

The malware include also a BASH shell script, attempts to erase partitions Unix systems, including Linux and HP-UX.

“The bash script is a wiper designed to work with any Linux distribution, with specific commands for SunOS, AIX, HP-UX distributions. It wipes out the /kernel, /usr, /etc, and /home directories.”

The discovery was announced by Symantec firms that dubbed it Jokra, following an extract from its blog post:

” The dropper for Trojan.Jokra contains a module for wiping remote Linux machines. We do not normally see components that work on multiple operating systems, so it is interesting to discover that the attackers included a component to wipe Linux machines inside a Windows threat.”

The trojan Jokra runs on Windows XP and 7 invoking an open source remote access manager, named mRemote, that could be used to manage devices on different platforms.

The malware is able to overwrite the Master Boot Record of the infected machine making impossible the bootstrapping, according McAfee analysis the agent wiped out the MBR on the hard drives overwriting it with either one of these strings:

PRINCIPES
HASTATI
PR!NCPES
HASTATI and PR!NCPES in combination
PRINCPES

Malware analysts at McAfee explained in their post on the topic:

“The attack also overwrote random parts of the file system with the same strings, rendering several files unrecoverable,” “So even if the MBR is recovered, the files on disk will be compromised too.”

“Three wipers are packaged as a position-independent executable (PIE) and a fourth as a dynamic-link library (DLL) injection. There are also some differences in regard to the timing.”

Another interesting behavior observed by researchers is that the malware also try to kill processes related two South Korean antivirus products commercialized by the companies Ahnlab and Hauri.

Avast security firm discovered the alleged source of the attack against Korean banks, it seems started from website of the Korean Software Property Right Council compromised to serve up an iframe that delivered an attack hosted on a third website.

Officials confirmed that the analysis of IP addresses did not reveal the real responsible for the attacks, due this reason Government of Seoul hasn’t speculated about the event, neither it has blamed North Korea, the situation is very complex and cyber attacks observed on this day may have been triggered by independent groups of hackers or by other states interested in exacerbating tensions in the area.

Who is responsible for the attacks?

Pierluigi Paganini

(Security Affairs – Malware)

Pierluigi Paganini

Pierluigi Paganini is member of the ENISA (European Union Agency for Network and Information Security) Threat Landscape Stakeholder Group and Cyber G7 Group, he is also a Security Evangelist, Security Analyst and Freelance Writer. Editor-in-Chief at "Cyber Defense Magazine", Pierluigi is a cyber security expert with over 20 years experience in the field, he is Certified Ethical Hacker at EC Council in London. The passion for writing and a strong belief that security is founded on sharing and awareness led Pierluigi to find the security blog "Security Affairs" recently named a Top National Security Resource for US. Pierluigi is a member of the "The Hacker News" team and he is a writer for some major publications in the field such as Cyber War Zone, ICTTF, Infosec Island, Infosec Institute, The Hacker News Magazine and for many other Security magazines. Author of the Books "The Deep Dark Web" and “Digital Virtual Currency and Bitcoin”.