Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 2087987e18915943…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:39:11 Authoring application: Microsoft Excel First seen: 2021-10-16
MD5: 1c76794277d309ecd1f13714422b49ce SHA-1: 4cabc850328c09aa9a806429a6cb64f365ea1f5b SHA-256: 2087987e189159437d766143f2f6739d58b47925651a15ba1c182d0147a72016
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 common technique for executing malicious code upon opening. The presence of dangerous formula APIs like RUN indicates the macro is designed to execute arbitrary commands. While the specific payload is not visible, the structure strongly suggests it acts as a downloader for further malicious activity.

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) 6423 bytes
SHA-256: cd956044dc5a3ff90c843b091a01a71be3d0b1922836d4ce8ee1e26d785e99b9
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 -  tWZVa
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H172 
' 0018     24 LABEL : Cell Value, String Constant - fUWLOhoIu len=0 
' 0018     20 LABEL : Cell Value, String Constant - HICGy len=0 
' 0018     21 LABEL : Cell Value, String Constant - JanFuk len=0 
' 0018     20 LABEL : Cell Value, String Constant - JlqYN len=0 
' 0018     23 LABEL : Cell Value, String Constant - kkipBRPN len=0 
' 0018     25 LABEL : Cell Value, String Constant - LCrodIHeSF len=0 
' 0018     23 LABEL : Cell Value, String Constant - lgEkAPAL len=0 
' 0018     25 LABEL : Cell Value, String Constant - NFqtYLevxn len=0 
' 0018     26 LABEL : Cell Value, String Constant - oInJCObicrT len=0 
' 0018     23 LABEL : Cell Value, String Constant - rNWZJtzd len=0 
' 0018     23 LABEL : Cell Value, String Constant - sRNzlOAX len=0 
' 0018     21 LABEL : Cell Value, String Constant - SYxqeY len=0 
' 0018     25 LABEL : Cell Value, String Constant - tVlOprdHoA len=0 
' 0018     22 LABEL : Cell Value, String Constant - tVuALeH len=0 
' 0018     23 LABEL : Cell Value, String Constant - uoXbcmVJ len=0 
' 0018     26 LABEL : Cell Value, String Constant - wfnVnimGhgm len=0 
' 0018     21 LABEL : Cell Value, String Constant - XDRWHI len=0 
' 0018     25 LABEL : Cell Value, String Constant - xUYJmcEYPs len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZLETDkwE len=0 
' 0018     24 LABEL : Cell Value, String Constant - znYpChdsm 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 LABE
... (truncated)

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