Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 676014f1caae99ff…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:30:33 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: e5379f9acbfead4ac8df3d7ba7af3d79 SHA-1: c18f364d658a75908b4c337ecaad0b314e3199f9 SHA-256: 676014f1caae99ff90697dd712a53b557013f7f23704a993ac07527ba62b458b
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, specifically using dangerous formula APIs like RUN. This strongly suggests the macro is designed to execute arbitrary code upon opening the workbook. The presence of a macro sheet named 'jpAp' and the Auto_Open label further confirm this. The macro likely acts as a downloader for a second-stage payload, although no specific URLs or hashes were extracted from this file.

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) 6408 bytes
SHA-256: 443b2c8f23f82b4b22a06eec7b8ebca82c34a3a74cd06d213b8463f8e9445ca9
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  jpAp
' 0018     20 LABEL : Cell Value, String Constant - ATkGI len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H190 
' 0018     21 LABEL : Cell Value, String Constant - bzaCpw len=0 
' 0018     27 LABEL : Cell Value, String Constant - CAKrjiFbccCB len=0 
' 0018     21 LABEL : Cell Value, String Constant - cdZRaR len=0 
' 0018     24 LABEL : Cell Value, String Constant - cFFatZrkk len=0 
' 0018     25 LABEL : Cell Value, String Constant - hjQmPypAnE len=0 
' 0018     21 LABEL : Cell Value, String Constant - HLSRll len=0 
' 0018     27 LABEL : Cell Value, String Constant - INjMfObQHQhl len=0 
' 0018     21 LABEL : Cell Value, String Constant - lZCTku len=0 
' 0018     26 LABEL : Cell Value, String Constant - MzXOSfBAgie len=0 
' 0018     25 LABEL : Cell Value, String Constant - orZgzvszcb len=0 
' 0018     21 LABEL : Cell Value, String Constant - phcKpo len=0 
' 0018     25 LABEL : Cell Value, String Constant - QqzwsbeaZH len=0 
' 0018     24 LABEL : Cell Value, String Constant - RQTqNKufo len=0 
' 0018     22 LABEL : Cell Value, String Constant - SHVpCKa len=0 
' 0018     25 LABEL : Cell Value, String Constant - SlfSNkxVlp len=0 
' 0018     24 LABEL : Cell Value, String Constant - ufsboMRXc len=0 
' 0018     24 LABEL : Cell Value, String Constant - vamJnNRoC len=0 
' 0018     22 LABEL : Cell Value, String Constant - WOrbrCR len=0 
' 0018     24 LABEL : Cell Value, String Constant - xickWXBBU 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
... (truncated)