Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 5da1ebb13fe8114a…

MALICIOUS

Office (OLE)

103.5 KB Created: 2020-07-08 07:27:00 Authoring application: Microsoft Excel First seen: 2020-07-24
MD5: 664518507fa491cb8970472be678c3fa SHA-1: db3570bd1e7da94cfcfa7ae45e3e057a0c28a612 SHA-256: 5da1ebb13fe8114a10ce5c08918c35010b32b1aefab96c0ffede51bef3e8def2
200 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The file contains Excel 4.0 macros, specifically an Auto_Open macro, which is a known technique for executing malicious code. The heuristics indicate the macro attempts environment evasion and uses dangerous formula APIs, suggesting it's designed to download and execute a second-stage payload. The presence of an Auto_Open macro strongly implies this file was delivered as a spearphishing attachment.

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.
  • XLM Auto_Open environment-evasion close gate critical OLE_XLM_ENVIRONMENT_EVASION_CLOSE
    Excel 4.0 macro sheet auto-executes environment checks with GET.WORKSPACE / GET.WINDOW, then shows a fake corruption/error message and closes the workbook when the host fails those checks. This is a malware sandbox-evasion pattern, even when the later payload stage is hidden behind obfuscated defined-name flow.
  • 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) 51512 bytes
SHA-256: cdaa64c3f5e1bb41a64e727ed0b771785c75b8cffd824b1e19fe3baa1e368b96
Preview script
First 1,000 lines of the extracted script
' 0085      9 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  
' 0085     23 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  MpFlsLTJojkinY
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0018     22 LABEL : Cell Value, String Constant - aehYxNG len=0 
' 0018     50 LABEL : Cell Value, String Constant - afndJRSQVszHkxwNRULkzscKNhKOcYHVuuV len=0 
' 0018     52 LABEL : Cell Value, String Constant - aqtwoNcVFnpKmrFPkxlXyVUvdugkLlwqJGcxW len=0 
' 0018     34 LABEL : Cell Value, String Constant - aQvqrpufmtKkkzqskKm len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  !IE54488 
' 0018     43 LABEL : Cell Value, String Constant - BbmgyvSoNFBNesOCLidHJpKPXNsC len=0 
' 0018     53 LABEL : Cell Value, String Constant - bmETablJEhjPWpwmSNOMRDJQhIHXNQIgJomUJd len=0 
' 0018     49 LABEL : Cell Value, String Constant - bmVUItVrESzRDHhVTNfcyVtyvHKZuvFPKn len=0 
' 0018     22 LABEL : Cell Value, String Constant - BxsKIeO len=0 
' 0018     35 LABEL : Cell Value, String Constant - cHiTjnphHjOyuiDtkyJr len=0 
' 0018     21 LABEL : Cell Value, String Constant - CmfmRe len=0 
' 0018     20 LABEL : Cell Value, String Constant - cMtwR len=0 
' 0018     63 LABEL : Cell Value, String Constant - CMuuhUuResZrdhHvsmFCYuTZVgjyUVfojNdvQjdTyHIGLwpw len=0 
' 0018     21 LABEL : Cell Value, String Constant - CxlHwn len=0 
' 0018     25 LABEL : Cell Value, String Constant - cyisyuHXYt len=0 
' 0018     38 LABEL : Cell Value, String Constant - CzFcjqVhhwBEvUjcMtwRtxM len=0 
' 0018     21 LABEL : Cell Value, String Constant - DgwdjD len=0 
' 0018     39 LABEL : Cell Value, String Constant - dgXwZFCkYtjaoyhhUUvERsNr len=0 
' 0018     24 LABEL : Cell Value, String Constant - DirrqvSZg len=0 
' 0018     26 LABEL : Cell Value, String Constant - DJFQhiEFPmT len=0 
' 0018     21 LABEL : Cell Value, String Constant - dqeQrO len=0 
' 0018     24 LABEL : Cell Value, String Constant - dTytusxip len=0 
' 0018     18 LABEL : Cell Value, String Constant - dUh len=0 
' 0018     39 LABEL : Cell Value, String Constant - DWpJEsYhiglWPXBONdhjbBQI len=0 
' 0018     23 LABEL : Cell Value, String Constant - eEgLvrfB len=0 
' 0018     24 LABEL : Cell Value, String Constant - EfCBcKbNR len=0 
' 0018     57 LABEL : Cell Value, String Constant - EfnBcvbzRrRcWoYuepvrDUiqrCZUxyfmFNDidechSZ len=0 
' 0018     22 LABEL : Cell Value, String Constant - efpytXm len=0 
' 0018     50 LABEL : Cell Value, String Constant - EGaDIVfBOCnPlkMtLwBbBMGYWsOmfbmESnb len=0 
' 0018     56 LABEL : Cell Value, String Constant - EgkyuerRRsBNpJoMeEepjClIrDIFQhvEFOmgKMsyS len=0 
' 0018     22 LABEL : Cell Value, String Constant - enMsWlS len=0 
' 0018     61 LABEL : Cell Value, String Constant - eqTmSpIhITNfPlVflhtLZhirPKnpWcvEtZUVTYJQXnOOdT len=0 
' 0018     22 LABEL : Cell Value, String Constant - ETmHZUJ len=0 
' 0018     22 LABEL : Cell Value, String Constant - EUuuKBD len=0 
' 0018     28 LABEL : Cell Value, String Constant - FaclvqTjCWpjZ len=0 
' 0018     22 LABEL : Cell Value, String Constant - FdjfqtJ len=0 
' 0018     54 LABEL : Cell Value, String Constant - FFEJfmtYlkBEHyXmfPwzUwBPMuIhhJRdGZFduUu len=0 
' 0018     51 LABEL : Cell Value, String Constant - fnoyWRuvcjCKzfabZePWdtVUkadUtWCyhVqg len=0 
' 0018     55 LABEL : Cell Value, String Constant - FOONSDvDhutKNQIgvoYHJdGLYiERFqSonPwOzEeE len=0 
' 0018     59 LABEL : Cell Value, String Constant - FpipUhgwBDuUjbMtvQsxLWqErdFbaCjBnrRrDwPMiFdV len=0 
' 0018     52 LABEL : Cell Value, String Constant - fqtJefoytXmGZsncIRSQVGyGkxwNRTLkzrcKM len=0 
' 0018     53 LABEL : Cell Value, String Constant - gJOcmHUItVrqSzREIhITNfcyVtlhtKZuirPKnp len=0 
' 0018     22 LABEL : Cell Value, String Constant - gmGOEje len=0 
' 0018     21 LABEL : Cell Value, String Cons
... (truncated)