Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 cb57bbae8e5ac0d6…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:39:22 Authoring application: Microsoft Excel First seen: 2021-06-20
MD5: f5c29f0507c18f26714e8b78285d2285 SHA-1: a306ddc686dde310900ea2028b2cddd3b1a592c0 SHA-256: cb57bbae8e5ac0d6881096fba1753105bb3cab476fdf6db77548b849c74eba91
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 upon opening the workbook. The presence of dangerous formula APIs like RUN further indicates malicious intent. The macro sheet itself contains obfuscated strings and data, suggesting an attempt to hide its true functionality.

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) 6385 bytes
SHA-256: 4221bf3a025978306a085b78d3b0cb302c55dd43f99f3c8310d74741886f0a13
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  Vmm
' 0018     25 LABEL : Cell Value, String Constant - AfLajaoiUW len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B149 
' 0018     26 LABEL : Cell Value, String Constant - dpckQhjbOWq len=0 
' 0018     24 LABEL : Cell Value, String Constant - EbrCCJXuJ len=0 
' 0018     26 LABEL : Cell Value, String Constant - EhagKxOBonQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - FbMZgtV len=0 
' 0018     27 LABEL : Cell Value, String Constant - FxHrlJZxmuHc len=0 
' 0018     24 LABEL : Cell Value, String Constant - iKHzuyMwj len=0 
' 0018     23 LABEL : Cell Value, String Constant - iZyHzMPw len=0 
' 0018     26 LABEL : Cell Value, String Constant - KUlwWDenrLV len=0 
' 0018     22 LABEL : Cell Value, String Constant - letNCKY len=0 
' 0018     21 LABEL : Cell Value, String Constant - LMITHs len=0 
' 0018     20 LABEL : Cell Value, String Constant - OszIr len=0 
' 0018     27 LABEL : Cell Value, String Constant - PThFxccEUYXk len=0 
' 0018     24 LABEL : Cell Value, String Constant - qQeQuWYQx len=0 
' 0018     20 LABEL : Cell Value, String Constant - QQVsy len=0 
' 0018     26 LABEL : Cell Value, String Constant - QVUGAQGWvGB len=0 
' 0018     27 LABEL : Cell Value, String Constant - sESgWHMhlbhX len=0 
' 0018     22 LABEL : Cell Value, String Constant - TbtYoAe len=0 
' 0018     20 LABEL : Cell Value, String Constant - VFgmV len=0 
' 0018     24 LABEL : Cell Value, String Constant - xZOMNTmIF 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 
... (truncated)

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