SystemExec Co., Ltd.
cephalus-apiThis record tracks a ransomware attack claimed by the cephalus-api group against SystemExec Co., Ltd.. It collects the publicly disclosed attack details — sector, location and timeline — as published on the operator's leak site and indexed by Breach House.
Window Zero
EXPOSURE GAPWindow Zero is the time the breach stayed in the open before anyone said so — the gap between when the attack was first discovered on the operator's leak site (t1) and when it was publicly disclosed (t2). The wider this window, the longer victims, staff and customers were exposed with no warning.
Attack Summary
system-exe.co.jp is the corporate site for SystemEXE, Inc., a Japan-based IT services company headquartered in Chuo-ku, Tokyo. The company was established in 1998 and offers system integration, product and service development, software development, business/technical solutions, and BPO-related services. Its official site also highlights strengths in database, cloud, and custom development work across sectors such as insurance, retail, manufacturing, healthcare, and accounting. In threat-intelligence listings, system-exe.co.jp was listed as a ransomware victim associated with cephalus-api.
Leak Screenshots
SAMPLEProof-of-breach screenshots the operator posted from the stolen data. Previews are redacted and locked — the originals are available on HaveIBeenRansom.