Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 aa43a0173f2a2ba3…

MALICIOUS

Office (OLE)

149.5 KB Created: 2020-07-09 10:29:46 Authoring application: Microsoft Excel First seen: 2020-09-15
MD5: daa44ecf68d1e253ea6ee80264251475 SHA-1: 0897bd18d2e57c19d531ca5bfedcddffe19494b8 SHA-256: aa43a0173f2a2ba38d22df91178a9783c42f4e2a9a0947592a3ede9eef05f96b
80 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The critical heuristic firing indicates the presence of an Excel 4.0 macro sheet with an Auto_Open defined name, which is a common technique for executing malicious code upon opening the document. The presence of XLM macros suggests an attempt to download and execute a secondary payload, although no specific URLs or commands were extracted from the provided evidence.

Heuristics 2

  • 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.
  • 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) 85997 bytes
SHA-256: 2ba4b73d4a3a1a4bd29409c938277686bbc21b12e9641aaae63e1a03882b8e40
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  SAx05
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  dxTHxamb
' 0018     30 LABEL : Cell Value, String Constant - appB hidden len=11 ptgArea3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\x00A\x0c2\rT\x00T\x00'
' 0018     29 LABEL : Cell Value, String Constant - AsjDVry hidden len=7 ptgRef3d  Sheet!CV3115 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgRef3d  Sheet!CV3115 
' 0018     29 LABEL : Cell Value, String Constant - DKkZaMz hidden len=7 ptgRef3d  Sheet!CV3119 
' 0018     31 LABEL : Cell Value, String Constant - ISNbi hidden len=11 ptgArea3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\x00\xb3\x0bP\x0cb\x00b\x00'
' 0018     29 LABEL : Cell Value, String Constant - kKX hidden len=11 ptgArea3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\x00 \x0c\x7f\x0ci\x00i\x00'
' 0018     30 LABEL : Cell Value, String Constant - LYxbjQNg hidden len=7 ptgRef3d  Sheet!CV3120 
' 0018     30 LABEL : Cell Value, String Constant - NqTO hidden len=11 ptgArea3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\x00\x9a\x0b"\x0cH\x00H\x00'
' 0018     28 LABEL : Cell Value, String Constant - PNGrFE hidden len=7 ptgRef3d  Sheet!CV3117 
' 0018     29 LABEL : Cell Value, String Constant - RcJufiP hidden len=7 ptgRef3d  Sheet!CV3121 
' 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, String Constant/ SST
' 00fd     10 LABELSST : Cell Va
... (truncated)

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