Experts finger disk-wiping badness used in S Korea megahack

The long, dark teatime of the Seoul


Antivirus firms have identified the main malware behind a major internet attack that hit corporate computer networks in South Korea on Wednesday afternoon. However the source and motives behind the attack remain a mystery. Researchers have dubbed it DarkSeoul.

Computer networks at three South Korean TV stations and at least two major banks - Shinhan and NongHyup - were crippled by data-wiping malware. Internet banking and ATM services at Shinhan Bank were reportedly affected by the surprise assault. Broadcasters KBS, MBC and YTN remained able to stick to their programming schedule despite being left with many hobbled PCs.

Screenshots of affected machines posted on Twitter show machines that failed to boot up properly.

At around the same time the website of Korean network provider LG U+ was defaced by the "Whois Team." The defacement featured a picture of three skulls together with alongside a taunting message that stated "User Accounts and All Data are in Our Hands. Unfortunately, We have deleted Your Data. We'll be back Soon."

LG U+ provided internet services for at least some of the firms involved and may have been a conduit in the attack.

The malware at the centre of the attack, dubbed DarkSeoul by Sophos and Jokra Trojan by Symantec, is not particularly sophisticated. "Sophos products have been able to detect the malware for nearly a year, and the various commands embedded in the malicious code have not been obfuscated," the antivirus firm reports.

Sophos said that DarkSeoul/Jokra attempts to disable two popular antivirus products developed in South Korea - AhnLab and Hauri AV. An analysis by South Korean antivirus firm AhnLab fails to mention this but does explain the data-wiping behaviour of the malware in some depth.

The malware "is a simple piece of code that overwrites the MBR (Master Boot Record) making the affected system unable to start after reboot", according to security tools firm AlienVault. AlienVault reckons a Chinese Exploit Kit named GonDad might have been involved in the spread of a family of related data-wiping malware. According to the security firm, Korean domains used to serve this exploit pack were registered using a Chinese email address. But hackers could easily have bought both the exploit kit and the email addresses from underground black markets so this doesn't really prove anything.

Zombie attack?

The speed at which the attack spread suggests that the wiper malware might have been distributed to already compromised clients in a zombie network, although AlienVault's Jaime Blasco is careful to note that his suspicion that a botnet was involved in the spread of the wiper malware remains only a theory.

Simon Edwards of AhnLab noted that a single Chinese IP address is being linked to the South Korea cyber-attack in some local reports. While the source of the attack remains unclear, restoration operations are underway, according to Edwards. He added that most locals appear to view the attacks as a continuation in the escalating tensions between North and South Korea over recent weeks following successful nuclear and rocket tests by Pyongyang.

A separate analysis by Symantec - which detects the same malware as the Jokra Trojan - has revealed that the malware contains a module for wiping Linux machines as well as the capability to wipe Windows PCs. The malware wipes the hard disks of infected computers and send them into a reboot, rendering them unusable in the process. The Jokra Trojan also attempts to wipe any drives attached or mapped to the compromised computer.

"While there are currently no indications of the source of this attack or the motivations behind it, it may be part of either a clandestine attack or the work of nationalistic hacktivists taking issues into their own hands," Symantec explains in a blog post, which also notes some similarities between the South Korean malware and the Shamoon attack against the corporate PC networks of Saudi Aramco and Qatari gas giant RasGas last year.

Meanwhile Trend Micro compares the behaviour of the MBR wiping malware to that of some strains of ransomware.

Both North and South Korea reportedly have maintained cyberwarfare units for several years. Five years ago, South Korea's military command and control centre was the target of a spyware attack from North Korea's electronic warfare division. The Mata Hari character at the centre of the case was convicted of seducing army officers in exchange for military secrets and jailed for five years.

A year later, in 2009, a massive DDoS attack crippled 26 South Korean and foreign governmental websites, including military sites. And two years after that, in 2011, the so-called "Ten Days of Rain" distributed denial-of-service [DDoS] attacks hit multiple government sites as well as the ground, air and naval divisions of the US armed forces stationed in South Korea.

Last week North Korea blamed the US and its allies for computer hacking attacks against its computer networks. ®

Broader topics


Other stories you might like

  • Twitter founder Dorsey beats hasty retweet from the board
    We'll see you around the Block

    Twitter has officially entered the post-Dorsey age: its founder and two-time CEO's board term expired Wednesday, marking the first time the social media company hasn't had him around in some capacity.

    Jack Dorsey announced his resignation as Twitter chief exec in November 2021, and passed the baton to Parag Agrawal while remaining on the board. Now that board term has ended, and Dorsey has stepped down as expected. Agrawal has taken Dorsey's board seat; Salesforce co-CEO Bret Taylor has assumed the role of Twitter's board chair. 

    In his resignation announcement, Dorsey – who co-founded and is CEO of Block (formerly Square) – said having founders leading the companies they created can be severely limiting for an organization and can serve as a single point of failure. "I believe it's critical a company can stand on its own, free of its founder's influence or direction," Dorsey said. He didn't respond to a request for further comment today. 

    Continue reading
  • Snowflake stock drops as some top customers cut usage
    You might say its valuation is melting away

    IPO darling Snowflake's share price took a beating in an already bearish market for tech stocks after filing weaker than expected financial guidance amid a slowdown in orders from some of its largest customers.

    For its first quarter of fiscal 2023, ended April 30, Snowflake's revenue grew 85 percent year-on-year to $422.4 million. The company made an operating loss of $188.8 million, albeit down from $205.6 million a year ago.

    Although surpassing revenue expectations, the cloud-based data warehousing business saw its valuation tumble 16 percent in extended trading on Wednesday. Its stock price dived from $133 apiece to $117 in after-hours trading, and today is cruising back at $127. That stumble arrived amid a general tech stock sell-off some observers said was overdue.

    Continue reading
  • Amazon investors nuke proposed ethics overhaul and say yes to $212m CEO pay
    Workplace safety, labor organizing, sustainability and, um, wage 'fairness' all struck down in vote

    Amazon CEO Andy Jassy's first shareholder meeting was a rousing success for Amazon leadership and Jassy's bank account. But for activist investors intent on making Amazon more open and transparent, it was nothing short of a disaster.

    While actual voting results haven't been released yet, Amazon general counsel David Zapolsky told Reuters that stock owners voted down fifteen shareholder resolutions addressing topics including workplace safety, labor organizing, sustainability, and pay fairness. Amazon's board recommended voting no on all of the proposals.

    Jassy and the board scored additional victories in the form of shareholder approval for board appointments, executive compensation and a 20-for-1 stock split. Jassy's executive compensation package, which is tied to Amazon stock price and mostly delivered as stock awards over a multi-year period, was $212 million in 2021. 

    Continue reading

Biting the hand that feeds IT © 1998–2022