Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b035013bf39de496…

MALICIOUS

Office (OLE)

3.26 MB First seen: 2026-05-11
MD5: c57dacf5966207c67f6fdd2e3fda0635 SHA-1: bdfa2863878f767455c33077f76163ca9114dc08 SHA-256: b035013bf39de49645644532d2b593eecb1388dc10bd638a3fbd469472c2d45d
62 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample is an OLE file identified as an Excel 4.0 macro sheet. While VBA macros could not be extracted, the presence of an XLM macro sheet suggests an attempt to execute arbitrary code. The NOP-equivalent sled and empty streams are indicative of obfuscation or anti-analysis techniques, common in malicious documents.

Heuristics 4

  • NOP-equivalent sled detected medium SC_NOP_EQUIV_SLED
    Long run of 0x41 bytes
    Disassembly
    Attempted x86 opcode disassembly
    00267681  41                inc ecx
    00267682  41                inc ecx
    00267683  41                inc ecx
    00267684  41                inc ecx
    00267685  41                inc ecx
    00267686  41                inc ecx
    00267687  41                inc ecx
    00267688  41                inc ecx
    00267689  41                inc ecx
    0026768A  41                inc ecx
    0026768B  41                inc ecx
    0026768C  41                inc ecx
    0026768D  41                inc ecx
    0026768E  41                inc ecx
    0026768F  41                inc ecx
    00267690  41                inc ecx
    00267691  41                inc ecx
    00267692  41                inc ecx
    00267693  41                inc ecx
    00267694  41                inc ecx
    00267695  41                inc ecx
    00267696  41                inc ecx
    00267697  41                inc ecx
    00267698  41                inc ecx
    00267699  41                inc ecx
    0026769A  41                inc ecx
    0026769B  41                inc ecx
    0026769C  41                inc ecx
    0026769D  41                inc ecx
    0026769E  41                inc ecx
    0026769F  41                inc ecx
    002676A0  41                inc ecx
    002676A1  41                inc ecx
    002676A2  41                inc ecx
    002676A3  41                inc ecx
    002676A4  41                inc ecx
    002676A5  41                inc ecx
    002676A6  41                inc ecx
    002676A7  79a3              jns 0x26764c
    002676A9  c41a              les ebx, ptr [edx]
    002676AB  127dc7            adc bh, byte ptr [ebp - 0x39]
    002676AE  f1                int1
    002676AF  c6                .byte 0xc6
    002676B0  d6                salc
    002676B1  dbc2              fcmovnb st(0), st(2)
    002676B3  b3ad              mov bl, 0xad
    002676B5  d48c              aam 0x8c
    002676B7  ba5e306f69        mov edx, 0x696f305e
    002676BC  ed                in eax, dx
    002676BD  b95a3667af        mov ecx, 0xaf67365a
    002676C2  fb                sti
    002676C3  22abd803db5b      and ch, byte ptr [ebx + 0x5bdb03d8]
    002676C9  10c8              adc al, cl
    002676CB  f1                int1
    002676CC  f5                cmc
    002676CD  4c                dec esp
    002676CE  ce                into
    002676CF  1e                push ds
    002676D0  2197c51a93e3      and dword ptr [edi - 0x1c6ce53b], edx
    002676D6  ea999ca7809989    ljmp 0x8999:0x80a79c99
    002676DD  54                push esp
    002676DE  88                .byte 0x88
    002676DF  35                .byte 0x35
    002676E0  6d                insd dword ptr es:[edi], dx
  • 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.
  • CFB header with no readable streams medium OLE_PARSE_EMPTY_STREAMS
    The file begins with a valid OLE2/CFB header but exposes no directory streams. A non-empty compound document with an unreadable directory is anomalous — it is seen with truncated/corrupt files and, more importantly, with content deliberately shifted off byte boundaries to defeat parsers while the host application still recovers the object.
  • Unsupported Office format for VBA extraction info OFFICE_FORMAT_UNSUPPORTED
    The Analyzer could not extract VBA macros: the document may be legacy, encrypted or malformed.