APT Attackers Target Japanese Word Processor Zero-Day

Symantec has issued an alert to warn organizations about targeted attacks against a previously undocumented security hole in Ichitaro, a word processing software program used by central and local governments as well as educational institutions in Japan.

Justsystems, the company that markets the Ichitaro software, has confirmed the issue and warns that live attacks are leading to full remote system compromise.

According to a post on the Symantec Security Response blog, the attacks may be linked to the APT 12 group that successfully hacked into the New York Times earlier this year.

Symantec said it first spotted attempts to exploit the Ichitaro vulnerability in September 2013.

“Our analysis revealed that the samples, detected as Trojan.Mdropper, for these attacks all contained the same back door Trojan, which Symantec detected as Backdoor.Vidgrab. If the exploit is successful, in theory the shell code would be executed to drop and launch the simplified Chinese version of notepad.exe while compromising the system, with the back door connecting to a remote site,” Symantec warned.

The company noted that the identical backdoor variant was used as a payload for a watering hole attack that hit a Microsoft Internet Explorer vulnerability which was patched in October 2013.

The research team is speculating that the same malware group is using vulnerabilities in multiple software to launch APT attacks.

“[This backdoor] is known to be used to target the Asia-Pacific region with government sectors being the primary targets according to Trend Micro. Symantec telemetries do not dispute this claim,” the company said. 

In the latest Ichitaro attacks, Symantec says the Trojan is delivered as e-mail attachments with Ichataro’s .jtd file extension. However, the malicious files are actually rich text format files that cannot be opened using Microsoft Word as they are designed to work only with Ichitaro.

“An interesting point of this attack campaign is that the malware group used unusual subject lines and email content that are not commonly used in targeted attacks,” Symantec said.

This is a classic spear-phishing attack that attempts to lure the targets to a popular Japanese online shopping site. If the target opens the file, the zero-day vulnerability is exploited and malware is placed on the machine that attempts to connect to a web site associated with the APT 12 group.

Security researchers are noticing a spike in advanced attacks against Japanese targets. Earlier this year, Kaspersky Lab warned about the Icefog cyber-espionage campaign that targeted governmental institutions, military contractors, maritime and ship-building groups, telecom operators, satellite operators, industrial and high technology companies and mass media, mainly in South Korea and Japan.