Zero-day vulnerability in Hancom Office

Type confusion

Trojan.Volgmer.B. Attackers from North Korea exploited the vulnerability HANGMAN in a word processor popular with the South Korea's government to steal the documents and upload them to a C&C server.
North Korea attack in June dubbed "Macktruck".

Vulnerability details

Advisory: SB2015090701 - Remote code execution in Hangul Word Processor

Vulnerable component: Hancom Office

CVE-ID: CVE-2015-6585

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-843 - Access of Resource Using Incompatible Type ('Type Confusion')


The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to type confusion error. A remote attacker can create a specially crafted HWPX file containing a set of directories and XML files, trick the victim into opening it, cause memory corruption and execute arbitrary code with privileges of the current user.

Successful exploitation of this vulnerability may result in arbitrary code execution on the vulnerable system.

Note: this vulnerability is being actively exploited.

Known APT campaigns:

Macktruck attack

The hackers performed the operation with the help of тАЬHangmanтАЭ malware. FireEye suspects North Korea of attack against South Korea.