Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f466a95407a29032…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:39:27 Authoring application: Microsoft Excel First seen: 2021-09-27
MD5: b867182b9a2a9b85527c01958decb96f SHA-1: bd418d3e6357dce50f4f61ad8017eb114fb2e300 SHA-256: f466a95407a290327dcc284794324857f2ed39831a2c956c3ec9f225e9c71b62
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook containing an Auto_Open entry, which is a critical finding indicating automatic execution upon opening. The presence of dangerous formula APIs, specifically the RUN function, strongly suggests the macro is designed to download and execute a secondary payload. This is a common technique for initial access via spearphishing attachments.

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) 6611 bytes
SHA-256: 4dde6d76a6bff820b161b2bd1628478f7518dcfb019c3494bffd02ffe9be1043
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 -  kOntE
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I173 
' 0018     20 LABEL : Cell Value, String Constant - EzgLh len=0 
' 0018     21 LABEL : Cell Value, String Constant - fAACgv len=0 
' 0018     21 LABEL : Cell Value, String Constant - FYEEpJ len=0 
' 0018     26 LABEL : Cell Value, String Constant - gMXDVvCVXhu len=0 
' 0018     23 LABEL : Cell Value, String Constant - HUXgORRx len=0 
' 0018     23 LABEL : Cell Value, String Constant - iuPEASBx len=0 
' 0018     21 LABEL : Cell Value, String Constant - JcUlqK len=0 
' 0018     21 LABEL : Cell Value, String Constant - kTQHyM len=0 
' 0018     26 LABEL : Cell Value, String Constant - PmVqqJLvULk len=0 
' 0018     22 LABEL : Cell Value, String Constant - RHKQaFM len=0 
' 0018     23 LABEL : Cell Value, String Constant - swyRHBty len=0 
' 0018     26 LABEL : Cell Value, String Constant - TkJgXDNnSKD len=0 
' 0018     27 LABEL : Cell Value, String Constant - UDBwCHExUCMx len=0 
' 0018     21 LABEL : Cell Value, String Constant - UiJANu len=0 
' 0018     20 LABEL : Cell Value, String Constant - UprAd len=0 
' 0018     20 LABEL : Cell Value, String Constant - WOVMV len=0 
' 0018     20 LABEL : Cell Value, String Constant - Wvhty len=0 
' 0018     27 LABEL : Cell Value, String Constant - YnjwgUxAmggL len=0 
' 0018     24 LABEL : Cell Value, String Constant - zDDQgBARQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - zNjYzweYTCe 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 
... (truncated)

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