Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 7ceb282897290b35…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:38:08 Authoring application: Microsoft Excel First seen: 2021-09-16
MD5: fd2c13d41aa7389178f19a6f7bf51883 SHA-1: 7c1781e8945cd67bf9f464357c03e36bfabdd5ad SHA-256: 7ceb282897290b35e2ef47f4fb389160d1529855537710904f46b4dc2c1f124c
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 function, which is a known method for executing malicious code. The presence of dangerous formula APIs like RUN indicates an intent to execute arbitrary commands. The macro sheet itself contains obfuscated strings and potentially malicious formulas, suggesting it's designed 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) 6371 bytes
SHA-256: f96a7c85cbffc1aae5b0d991c5a83f8ac166e0194969680b88b528f38cbe36e9
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 -  sDFD
' 0018     25 LABEL : Cell Value, String Constant - amfNUHUmYD len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F146 
' 0018     25 LABEL : Cell Value, String Constant - BkxZpuuncP len=0 
' 0018     20 LABEL : Cell Value, String Constant - CpZoL len=0 
' 0018     25 LABEL : Cell Value, String Constant - EwbfRfctFT len=0 
' 0018     25 LABEL : Cell Value, String Constant - gWJJLNOWpx len=0 
' 0018     27 LABEL : Cell Value, String Constant - jVdXcBrkibbU len=0 
' 0018     20 LABEL : Cell Value, String Constant - KFfkR len=0 
' 0018     26 LABEL : Cell Value, String Constant - NjBZlwTemgM len=0 
' 0018     20 LABEL : Cell Value, String Constant - OllFd len=0 
' 0018     25 LABEL : Cell Value, String Constant - ovjyEJIkSQ len=0 
' 0018     27 LABEL : Cell Value, String Constant - psquTmttYQym len=0 
' 0018     21 LABEL : Cell Value, String Constant - QKDkUu len=0 
' 0018     20 LABEL : Cell Value, String Constant - QVVkA len=0 
' 0018     21 LABEL : Cell Value, String Constant - raZerH len=0 
' 0018     24 LABEL : Cell Value, String Constant - tlaMcmioh len=0 
' 0018     21 LABEL : Cell Value, String Constant - uasIAd len=0 
' 0018     24 LABEL : Cell Value, String Constant - WwHPiqzKF len=0 
' 0018     20 LABEL : Cell Value, String Constant - xsLsS len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZbpJZFTF len=0 
' 0018     20 LABEL : Cell Value, String Constant - zFbNV 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 LABELSST 
... (truncated)

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