The Siemens S7-200 (CPU 221, 222, 224, 226) uses a protection scheme that was historically vulnerable to "brute-force" or "recovery" utilities because the password protection was implemented at the firmware level rather than via a cryptographically secure hash.
Tools associated with this era:
For legitimate recovery:
The date "2006 09 11" likely refers to the release date of a specific software bundle or forum post that circulated on industrial automation forums (such as "Automation Direct" or older Russian engineering forums). During this period, several tools became public that targeted the relatively weak security of Siemens S7-200 and S7-300 PLCs from that era.
Searching for simatic s7 200 s7 300 mmc password unlock 2006 09 11 reveals a specific community-driven knowledge base. The exact phrasing is used by:
The date itself has become a “magic number” in automation folklore, comparable to the “12345678” password for old Allen-Bradley PLCs.