TrendLabs has received several reports a malicious Ichitaro document taking advantage of an as-yet undetermined vulnerability to drop a Trojan on target machines. Ichitaro is a popular Japanese word processing application.
The said exploit, which Trend Micro will detect as TROJ_TARODROP.Q, drops a Trojan to be detected as TROJ_SMALL.GQM. Based on initial analysis, TROJ_SMALL.GQM has the capability to drop other files onto the system, thus exposing the compromised machine to other attacks. More details about these malware will be posted shortly in the Trend Micro Virus Encyclopedia.
Note that this is not the first time a Japanese application was exploited by malware authors to perform their malicious deeds. Around the same time last year, the first Ichitaro exploit — TROJ_MDROPPER.BL — was detected (several variants has since followed). More recently, a vulnerability in the Japanese archiving application Lhaca was exploited by TROJ_LHDROPPER.A to drop a backdoor program.