Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3f773358484dca53…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:39:10 Authoring application: Microsoft Excel First seen: 2021-10-02
MD5: 374ec5d2d99f958abad92bb602457cf7 SHA-1: 38ff24e228d4fc8af9399560c69bba7a0b8b6a37 SHA-256: 3f773358484dca5314b0fa3fbd369ab58d130abb137aa2c2dc1421d32982a018
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 sheet containing an Auto_Open defined name, indicating it will execute automatically upon opening. Heuristics indicate the use of dangerous formula APIs, suggesting the macro is designed to perform malicious actions, likely downloading and executing a second-stage payload. No specific family could be identified.

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) 6587 bytes
SHA-256: 8c68037c14c8ee0cb579a229c5dbe77d7f1ae89b1cd46d41a07b7a1b50ea86ce
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  bzUNFngp
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D161 
' 0018     25 LABEL : Cell Value, String Constant - HAeYNSTAEw len=0 
' 0018     27 LABEL : Cell Value, String Constant - HycInILBpuDK len=0 
' 0018     25 LABEL : Cell Value, String Constant - IWAoUKwNPr len=0 
' 0018     26 LABEL : Cell Value, String Constant - IWnoFZRFFzf len=0 
' 0018     26 LABEL : Cell Value, String Constant - jXUyXKCKelO len=0 
' 0018     20 LABEL : Cell Value, String Constant - KuLDK len=0 
' 0018     24 LABEL : Cell Value, String Constant - lHMyJviJr len=0 
' 0018     27 LABEL : Cell Value, String Constant - lzboVVpbbYUH len=0 
' 0018     23 LABEL : Cell Value, String Constant - MtLQOMBD len=0 
' 0018     25 LABEL : Cell Value, String Constant - nRYOyqPtby len=0 
' 0018     22 LABEL : Cell Value, String Constant - qUIGFJJ len=0 
' 0018     23 LABEL : Cell Value, String Constant - SzksqsCV len=0 
' 0018     22 LABEL : Cell Value, String Constant - tKRfsTY len=0 
' 0018     21 LABEL : Cell Value, String Constant - UCGzdZ len=0 
' 0018     23 LABEL : Cell Value, String Constant - USWbBRqe len=0 
' 0018     22 LABEL : Cell Value, String Constant - VtAYOja len=0 
' 0018     21 LABEL : Cell Value, String Constant - VypVhy len=0 
' 0018     27 LABEL : Cell Value, String Constant - xCBzcuSyzdek len=0 
' 0018     26 LABEL : Cell Value, String Constant - XcGNwEhaAgK len=0 
' 0018     27 LABEL : Cell Value, String Constant - YWtUGxzzYgTM 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/ 
... (truncated)

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