Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a22e543915cfa75f…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-27 11:44:30 Authoring application: Microsoft Excel First seen: 2021-06-17
MD5: e8bfe9a259bfd43192363ad62eb56392 SHA-1: 827285ad6bfd487533b7790dab3da1bde65eb99b SHA-256: a22e543915cfa75f7bb770c17e63305af8d123af8f34386323366a072502178c
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook containing an Auto_Open function, which is a critical indicator of malicious intent. This function is designed to execute arbitrary code upon opening the workbook. The presence of dangerous formula APIs like RUN further supports the conclusion that this macro is intended to download and execute a second-stage 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) 6759 bytes
SHA-256: 199ef4477b318852785dd05891d4aff389edd88f95efd84080c03d554baf0931
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  kLeQfjyVK
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C136 
' 0018     20 LABEL : Cell Value, String Constant - ayoLm len=0 
' 0018     23 LABEL : Cell Value, String Constant - CvtKbflR len=0 
' 0018     20 LABEL : Cell Value, String Constant - gQFrG len=0 
' 0018     22 LABEL : Cell Value, String Constant - IXPKvNU len=0 
' 0018     23 LABEL : Cell Value, String Constant - jYmarCJb len=0 
' 0018     25 LABEL : Cell Value, String Constant - MKdGekUeNq len=0 
' 0018     21 LABEL : Cell Value, String Constant - mnVvQk len=0 
' 0018     21 LABEL : Cell Value, String Constant - mQhtrn len=0 
' 0018     25 LABEL : Cell Value, String Constant - NtwoPqUWpV len=0 
' 0018     23 LABEL : Cell Value, String Constant - QCTiTjWS len=0 
' 0018     20 LABEL : Cell Value, String Constant - qKSOb len=0 
' 0018     20 LABEL : Cell Value, String Constant - RDPVm len=0 
' 0018     27 LABEL : Cell Value, String Constant - sMBIhmdcUsNM len=0 
' 0018     27 LABEL : Cell Value, String Constant - sPyBrYUygvTr len=0 
' 0018     26 LABEL : Cell Value, String Constant - sUGbuiHhkMa len=0 
' 0018     24 LABEL : Cell Value, String Constant - uyVQXLeMS len=0 
' 0018     23 LABEL : Cell Value, String Constant - wnRVSQIX len=0 
' 0018     20 LABEL : Cell Value, String Constant - XEwqm len=0 
' 0018     23 LABEL : Cell Value, String Constant - zpIMonVG len=0 
' 0018     24 LABEL : Cell Value, String Constant - zUlaOmlWs 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 LABELS
... (truncated)