Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 86bf07da8a34380c…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:40:20 Authoring application: Microsoft Excel First seen: 2020-12-25
MD5: 7bc9e10c7a39791e6073fecc1a1df2b2 SHA-1: b195e5734f583c3124ed79cd07087ee8732edded SHA-256: 86bf07da8a34380cfbdf909953c8e77b385791f729a90cf4d8c20f165c5aa4bc
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding. This indicates the macro sheet is designed to execute automatically upon opening the workbook. The presence of dangerous formula APIs, including the RUN function, suggests the macro is intended to execute arbitrary commands, likely to download and run a secondary payload.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6356 bytes
SHA-256: 707a78be5c80a230f55f4ac95bbce6cdcac85338e0d0c32fa25db3424fe8e5f9
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  psN
' 0018     26 LABEL : Cell Value, String Constant - aRirEUsAyIT len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H143 
' 0018     22 LABEL : Cell Value, String Constant - BEWFFfd len=0 
' 0018     21 LABEL : Cell Value, String Constant - bwBjXe len=0 
' 0018     20 LABEL : Cell Value, String Constant - DBhav len=0 
' 0018     20 LABEL : Cell Value, String Constant - Dnhbb len=0 
' 0018     27 LABEL : Cell Value, String Constant - fiKSlEDINLwF len=0 
' 0018     22 LABEL : Cell Value, String Constant - FMKxsFs len=0 
' 0018     23 LABEL : Cell Value, String Constant - FRUAUxpF len=0 
' 0018     21 LABEL : Cell Value, String Constant - ivJYya len=0 
' 0018     21 LABEL : Cell Value, String Constant - lEPucR len=0 
' 0018     22 LABEL : Cell Value, String Constant - lqKIGvM len=0 
' 0018     21 LABEL : Cell Value, String Constant - ogrwLl len=0 
' 0018     20 LABEL : Cell Value, String Constant - orZJy len=0 
' 0018     20 LABEL : Cell Value, String Constant - QIZsv len=0 
' 0018     21 LABEL : Cell Value, String Constant - ShBLhV len=0 
' 0018     20 LABEL : Cell Value, String Constant - sMTpF len=0 
' 0018     26 LABEL : Cell Value, String Constant - SOPTxLYscMM len=0 
' 0018     26 LABEL : Cell Value, String Constant - VBTSgkQONGM len=0 
' 0018     24 LABEL : Cell Value, String Constant - YbxcDtxJX len=0 
' 0018     20 LABEL : Cell Value, String Constant - zXFOg len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, Str
... (truncated)

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