Program Organization Units
Program Organizational Units (POUs) are block structures used within PLC programming to create programs and projects. [1] POUs can be used to hold user programs written in IEC 61131-3 languages: Structured text, Instruction list, Function block, and Ladder logic. [1] Application - 201203 They can also provide additional functionality, such as establishing connections between the PLC and other devices using TCON. [2] Stuxnet uses a simple code-prepending infection technique to infect Organization Blocks (OB). For example, the following sequence of actions is performed when OB1 is infected [3]: *Increase the size of the original block. *Write malicious code to the beginning of the block. *Insert the original OB1 code after the malicious code.
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Program Organization Units
Program Organizational Units (POUs) are block structures used within PLC programming to create programs and projects. [1] POUs can be used to hold user programs written in IEC 61131-3 languages: Structured text, Instruction list, Function block, and Ladder logic. [1] Application - 201203 They can also provide additional functionality, such as establishing connections between the PLC and other devices using TCON. [2] Stuxnet uses a simple code-prepending infection technique to infect Organization Blocks (OB). For example, the following sequence of actions is performed when OB1 is infected [3]: *Increase the size of the original block. *Write malicious code to the beginning of the block. *Insert the original OB1 code after the malicious code.
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Object version and sync metadata
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Imported snapshots across ATT&CK releases (1)
| Release | Bundle imported | Object version | Modified | Status | Raw hash |
|---|---|---|---|---|---|
| 19.1 | 1.0 | Current bundle Deprecated | bddbe4341359… |
Mirrored ATT&CK source object
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External references and citations
MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.
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[1]
Guidance - IEC61131
John Karl-Heinz. (n.d.). Programming Industrial Automation Systems. Retrieved October 22, 2019.
Open source URL -
[2]
PLCBlaster - Spenneberg
Spenneberg, Ralf, Maik Brüggemann, and Hendrik Schwartke. (2016, March 31). Plc-blaster: A worm living solely in the plc.. Retrieved September 19, 2017.
Open source URL -
[3]
Stuxnet - Symantec - 201102
Nicolas Falliere, Liam O Murchu, Eric Chien. (2011, February). W32.Stuxnet Dossier (Version 1.4). Retrieved September 22, 2017.
Open source URL -
[4]
mitre-ics-attack T0844Open source URL
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