Obfuscated XLM Auto_Open execution chain

OLE_XLM_OBFUSCATED_AUTOEXEC_CHAIN

← All detection heuristics · Office

critical OLE_XLM_OBFUSCATED_AUTOEXEC_CHAIN

What it means

XLM macro sheet auto-executes an obfuscated formula/RUN chain.

Why it fires

Excel 4.0 macro malware commonly hides its command text in formula arithmetic, reconstructs strings with FORMULA(CHAR(...)), stores intermediate values through SET.VALUE / GET.CELL / GOTO, and transfers execution with RUN(). Behind Auto_Open, this sequence executes the reconstructed stage even when no VBA project exists.

Other Office heuristics

OLE_VBA_AFFINE_MSI_DOWNLOADER OLE_VBA_AUTOEXEC_FRAGMENTED_SHELL OLE_VBA_DESTRUCTIVE_WORKBOOK_SHUTDOWN OLE_VBA_BIDIRECTIONAL_MACROCOPY_REPLICATION OOXML_BRAND_LINK_MISMATCH_LURE CVE_2016_7262 POLYGLOT_OOXML_REL_COMMAND OLE_RAW_PCODE_CROSS_DOCUMENT_REPLICATION OLE_VBA_CROSS_WORKBOOK_REPLICATION OOXML_XLM_DANGEROUS_FN OFFICE_DEFAULT_PASSWORD_VBA_DROP_EXEC OFFICE_EMBEDDED_SWF EMBEDDED_OFFICE_CHILD_STATIC_TRIAGE OFFICE_EMBEDDED_MACRO_OBJECT OLE_EMBEDDED_EXE OLE_VBA_EMBEDDED_PE_DROPPER OLE_ENCRYPTED_AND_MALFORMED CVE_2017_11882_EQUATION_NATIVE_CMD_RELATED CVE_2017_11882 OLE_EQUATION_OLE10NATIVE_DOWNLOADER OLE_MTEF_NATIVE_CODE_STUB OLE_EQUATION_OLE10NATIVE_SHELLCODE OOXML_XLM_MACRO_IN_WORKSHEET OLE_XLS5_LAROUX_MACRO_VIRUS