Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f3f0699b3ae71fd9…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:47:19 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: 36b2169ca82eec783abb8a6cf50a4572 SHA-1: 41852d9bc296cb3535f92f468f11ea2fd0811eb4 SHA-256: f3f0699b3ae71fd90af7836f388503f408cab13e909a85d744923a1224d25bad
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a known technique for executing malicious code upon opening the workbook. The presence of dangerous formula APIs further indicates malicious intent. The macro sheet itself contains obfuscated strings and potentially commands, but the primary threat is the Auto_Open execution.

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) 6705 bytes
SHA-256: 66262a982b818641e4265e62ebee9860201db6c663fef5759718fdd31a1395a1
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  GzLaTMq
' 0018     23 LABEL : Cell Value, String Constant - AlbNKLTi len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G181 
' 0018     24 LABEL : Cell Value, String Constant - fipNthfPQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - icefOWdaPXC len=0 
' 0018     23 LABEL : Cell Value, String Constant - lelVrIJA len=0 
' 0018     22 LABEL : Cell Value, String Constant - lhwhHLx len=0 
' 0018     27 LABEL : Cell Value, String Constant - LKEtWRPNMoat len=0 
' 0018     23 LABEL : Cell Value, String Constant - lTPIkFzH len=0 
' 0018     22 LABEL : Cell Value, String Constant - lvXECov len=0 
' 0018     20 LABEL : Cell Value, String Constant - MCtms len=0 
' 0018     24 LABEL : Cell Value, String Constant - mLSqEryFj len=0 
' 0018     22 LABEL : Cell Value, String Constant - OeSivqT len=0 
' 0018     20 LABEL : Cell Value, String Constant - qmBUc len=0 
' 0018     23 LABEL : Cell Value, String Constant - rQpwtkff len=0 
' 0018     26 LABEL : Cell Value, String Constant - rzugRkYwVCT len=0 
' 0018     23 LABEL : Cell Value, String Constant - uaAIuaSj len=0 
' 0018     24 LABEL : Cell Value, String Constant - UBPsHWwTC len=0 
' 0018     21 LABEL : Cell Value, String Constant - UMskWu len=0 
' 0018     22 LABEL : Cell Value, String Constant - WCmlkTU len=0 
' 0018     25 LABEL : Cell Value, String Constant - WketSyzkGL len=0 
' 0018     24 LABEL : Cell Value, String Constant - wreAWVAPs 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 L
... (truncated)

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