Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ef3454616bd7522f…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:43:57 Authoring application: Microsoft Excel First seen: 2021-10-14
MD5: aadccb444167c87021c0c4a6bef7412d SHA-1: 5613ba646c007bb5b24009295cc6247f4365fec2 SHA-256: ef3454616bd7522f3a54b5c0829cbcb6259980693b7cf4cd4a20b7f160b5fb09
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 defined name, which is a critical indicator of malicious intent. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code. This is a common technique for downloading and executing further stages of malware.

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) 6622 bytes
SHA-256: b8eb4fbea1416ba4585b7bd56b93d94eb009600c3a0cda6a7fb37e9d1f904901
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  EWdTV
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I196 
' 0018     20 LABEL : Cell Value, String Constant - CvRYH len=0 
' 0018     21 LABEL : Cell Value, String Constant - CWiEzK len=0 
' 0018     26 LABEL : Cell Value, String Constant - epJWKWKbDtP len=0 
' 0018     20 LABEL : Cell Value, String Constant - gGTlb len=0 
' 0018     22 LABEL : Cell Value, String Constant - HIHJUOJ len=0 
' 0018     23 LABEL : Cell Value, String Constant - JyFWeibR len=0 
' 0018     24 LABEL : Cell Value, String Constant - kHtqJCyvN len=0 
' 0018     25 LABEL : Cell Value, String Constant - QHNfzxkyzd len=0 
' 0018     24 LABEL : Cell Value, String Constant - QHQdpOYDk len=0 
' 0018     21 LABEL : Cell Value, String Constant - RwRudE len=0 
' 0018     23 LABEL : Cell Value, String Constant - smdqJgJl len=0 
' 0018     27 LABEL : Cell Value, String Constant - SRpNeFHuefiP len=0 
' 0018     26 LABEL : Cell Value, String Constant - svoopYxApvi len=0 
' 0018     22 LABEL : Cell Value, String Constant - UeBpdwz len=0 
' 0018     23 LABEL : Cell Value, String Constant - VkHrDCAj len=0 
' 0018     23 LABEL : Cell Value, String Constant - xMbNyhVd len=0 
' 0018     22 LABEL : Cell Value, String Constant - XnwmuVh len=0 
' 0018     25 LABEL : Cell Value, String Constant - XsWXRGaqTL len=0 
' 0018     23 LABEL : Cell Value, String Constant - YtwbkwgZ len=0 
' 0018     25 LABEL : Cell Value, String Constant - zEHulkDcoz 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 LA
... (truncated)

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