Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c1fa7c013c9204eb…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:39:00 Authoring application: Microsoft Excel First seen: 2021-06-28
MD5: 1a9ea2a6b5caa33fdbf6da1b4dd6022b SHA-1: 6621645fd49356b51b21f056a05af6a61d2c4232 SHA-256: c1fa7c013c9204ebf4c642e32aa113826368ed8a6c804129631098e7f93e7ac5
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, which is a common method for executing malicious code upon opening the document. The `RUN=0` formula API suggests the macro is designed to execute an external command or payload. The truncated document body and script content prevent a more specific analysis of the payload or its ultimate destination.

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) 6448 bytes
SHA-256: b5789539060afc5e1ef0e285c1037506ca98df166cf95d4e81c13a12fa764f8b
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 -  NXO
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G155 
' 0018     24 LABEL : Cell Value, String Constant - AYgHUIrRD len=0 
' 0018     22 LABEL : Cell Value, String Constant - blwyNhQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - FazaJhf len=0 
' 0018     26 LABEL : Cell Value, String Constant - fPhSeeaxJpu len=0 
' 0018     22 LABEL : Cell Value, String Constant - IDeXNpS len=0 
' 0018     26 LABEL : Cell Value, String Constant - KaaqfmLnGQw len=0 
' 0018     25 LABEL : Cell Value, String Constant - KYHlCLHjBY len=0 
' 0018     23 LABEL : Cell Value, String Constant - LOPxXZxT len=0 
' 0018     25 LABEL : Cell Value, String Constant - OBNrhPaZxa len=0 
' 0018     24 LABEL : Cell Value, String Constant - othLnaHYK len=0 
' 0018     22 LABEL : Cell Value, String Constant - PyWvfiP len=0 
' 0018     27 LABEL : Cell Value, String Constant - qTNmOCJIETGJ len=0 
' 0018     20 LABEL : Cell Value, String Constant - SQdnt len=0 
' 0018     22 LABEL : Cell Value, String Constant - weoDcwz len=0 
' 0018     26 LABEL : Cell Value, String Constant - wiwgaWcmJJf len=0 
' 0018     23 LABEL : Cell Value, String Constant - WQtsmbGW len=0 
' 0018     26 LABEL : Cell Value, String Constant - WSQyyDBSaSu len=0 
' 0018     20 LABEL : Cell Value, String Constant - wVFjU len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZuKQIrs len=0 
' 0018     27 LABEL : Cell Value, String Constant - ZxoLnVdHTAGi 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   
... (truncated)