Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 2e4b81a97f688baf…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:40:38 Authoring application: Microsoft Excel First seen: 2021-10-14
MD5: 1a8e7d7dda201533ca570b22b1952dd2 SHA-1: 2871ef088efc51fe3a88846b0c00b76a083b1adb SHA-256: 2e4b81a97f688baf091b28910e2ed3fe07bb0462089ac9a645d322de87c48bb6
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file is an Excel document containing Excel 4.0 macros, specifically triggering an Auto_Open function. This indicates an attempt to automatically execute code upon opening the document. The presence of dangerous formula APIs in the Auto_Open macro suggests it is designed to perform malicious actions, such as downloading and executing a secondary 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) 6891 bytes
SHA-256: 41c66eabdf0338a258c3b0099cd2be7d5225f785a4b5cc4a85fd7b89dc7f24c5
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     19 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  RHttOFGnHz
' 0018     26 LABEL : Cell Value, String Constant - aIyOYDVwKyf len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D158 
' 0018     24 LABEL : Cell Value, String Constant - CSJTozCZO len=0 
' 0018     22 LABEL : Cell Value, String Constant - fLufdzR len=0 
' 0018     23 LABEL : Cell Value, String Constant - IEidLKds len=0 
' 0018     25 LABEL : Cell Value, String Constant - IKgwaVpCcP len=0 
' 0018     20 LABEL : Cell Value, String Constant - JNHvF len=0 
' 0018     26 LABEL : Cell Value, String Constant - JtgOrBVabyD len=0 
' 0018     26 LABEL : Cell Value, String Constant - JZlmNYgOCVx len=0 
' 0018     23 LABEL : Cell Value, String Constant - MCwpsuKn len=0 
' 0018     27 LABEL : Cell Value, String Constant - MjoWLSxLzHNM len=0 
' 0018     26 LABEL : Cell Value, String Constant - oANFSvmIEZt len=0 
' 0018     23 LABEL : Cell Value, String Constant - OGbBSoto len=0 
' 0018     26 LABEL : Cell Value, String Constant - pvIuMXPWkUl len=0 
' 0018     24 LABEL : Cell Value, String Constant - QPusrabvc len=0 
' 0018     24 LABEL : Cell Value, String Constant - TXukGTUVy len=0 
' 0018     27 LABEL : Cell Value, String Constant - vDTomauWGafR len=0 
' 0018     23 LABEL : Cell Value, String Constant - VUWQKujL len=0 
' 0018     23 LABEL : Cell Value, String Constant - XvRyZFMO len=0 
' 0018     26 LABEL : Cell Value, String Constant - xwaHBHfEIIi len=0 
' 0018     26 LABEL : Cell Value, String Constant - zduhAVjunvk 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 
... (truncated)

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