Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a9bf9b90effbd153…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:40:43 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: 9f940e6abf89a97b907a1bb89bdceb95 SHA-1: 8ed0ec3ce20f274cb5c6d03bfcf9c4d4204c45ba SHA-256: a9bf9b90effbd153ed474294d482cd8bb7ddc9a4b326599c01c042a737c70a76
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 in the Auto_Open macro indicates an intent to run arbitrary commands. While the specific payload is not directly visible, the macro's execution is the primary attack vector.

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) 6631 bytes
SHA-256: 210ddc79a784b6c95942a8d82964d57c27ae8b4591d30266d94dbb35242b43d2
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  KfuZhX
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F189 
' 0018     21 LABEL : Cell Value, String Constant - gTlXOe len=0 
' 0018     26 LABEL : Cell Value, String Constant - HTDrLuHDfxv len=0 
' 0018     27 LABEL : Cell Value, String Constant - IOYIPpUuOQQf len=0 
' 0018     23 LABEL : Cell Value, String Constant - jJxBifba len=0 
' 0018     25 LABEL : Cell Value, String Constant - kMsKXYaWtY len=0 
' 0018     27 LABEL : Cell Value, String Constant - MRYDbqtGHzVU len=0 
' 0018     25 LABEL : Cell Value, String Constant - pDxCNuyAIN len=0 
' 0018     23 LABEL : Cell Value, String Constant - PqRwWDZj len=0 
' 0018     25 LABEL : Cell Value, String Constant - qrofmSjNuR len=0 
' 0018     25 LABEL : Cell Value, String Constant - rgZabKkkhO len=0 
' 0018     26 LABEL : Cell Value, String Constant - SwLZOogLmUr len=0 
' 0018     25 LABEL : Cell Value, String Constant - TeBYWWMvEW len=0 
' 0018     24 LABEL : Cell Value, String Constant - TzSiSAAxV len=0 
' 0018     26 LABEL : Cell Value, String Constant - uhTcVjKUggo len=0 
' 0018     27 LABEL : Cell Value, String Constant - VZvdrXmFEqlu len=0 
' 0018     26 LABEL : Cell Value, String Constant - wSiZzvJimRy len=0 
' 0018     20 LABEL : Cell Value, String Constant - XMNHl len=0 
' 0018     25 LABEL : Cell Value, String Constant - xxNgscFqaW len=0 
' 0018     26 LABEL : Cell Value, String Constant - ZLUTaXJzawq len=0 
' 0018     27 LABEL : Cell Value, String Constant - zyULoxUkjNsm 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, St
... (truncated)

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