Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 446435da5ebad45f…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:41:36 Authoring application: Microsoft Excel First seen: 2021-09-15
MD5: f291ef6d1b4ec091149122c6e46ab064 SHA-1: 1c6f612b955eeb48cb469b5c96a59a14a96b77a3 SHA-256: 446435da5ebad45fcefcaf901a8d83040afc1a2987eeacc12fc6cab077785b4a
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 (XLM) macros. The presence of an Auto_Open defined name and the use of dangerous formula APIs like RUN indicate that the macro is designed to execute arbitrary code upon opening. This is a common technique for delivering secondary payloads.

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) 6514 bytes
SHA-256: 0eb049607427a0b2cda62581c590cd33e8c89214f12e9879a48fcb7d5fe189e2
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  fmDdguw
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I179 
' 0018     27 LABEL : Cell Value, String Constant - CqToBmOMcdii len=0 
' 0018     21 LABEL : Cell Value, String Constant - CuZqov len=0 
' 0018     21 LABEL : Cell Value, String Constant - cwMNEa len=0 
' 0018     21 LABEL : Cell Value, String Constant - cZRrMR len=0 
' 0018     27 LABEL : Cell Value, String Constant - EmahPfiXqKaP len=0 
' 0018     27 LABEL : Cell Value, String Constant - JLqAgNFcoeBt len=0 
' 0018     20 LABEL : Cell Value, String Constant - jPvRT len=0 
' 0018     27 LABEL : Cell Value, String Constant - lrftvrecHbhx len=0 
' 0018     22 LABEL : Cell Value, String Constant - LSuXxAf len=0 
' 0018     23 LABEL : Cell Value, String Constant - mSHbNrDR len=0 
' 0018     25 LABEL : Cell Value, String Constant - NJSkxOMZQV len=0 
' 0018     24 LABEL : Cell Value, String Constant - pNhRBmWiE len=0 
' 0018     24 LABEL : Cell Value, String Constant - rOcHNcFkY len=0 
' 0018     22 LABEL : Cell Value, String Constant - RrZvPun len=0 
' 0018     22 LABEL : Cell Value, String Constant - veybtEI len=0 
' 0018     25 LABEL : Cell Value, String Constant - wXFsWZZNZQ len=0 
' 0018     25 LABEL : Cell Value, String Constant - xJBTogEaoz len=0 
' 0018     22 LABEL : Cell Value, String Constant - XLbpDzE len=0 
' 0018     25 LABEL : Cell Value, String Constant - XyzkREehBy len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZtpZxgXU 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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