Xls.Downloader.94c25b356b5a6cac-9978798-0 — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 60b7371baf1af315…

MALICIOUS

Office (OLE) / .XLS

1.05 MB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2023-08-08
MD5: dbc4d10414eb41bf8020c4a36326288b SHA-1: 6b910b8627b7048011ec710e636b9c7b8a1cb5a3 SHA-256: 60b7371baf1af315fdf5a09b71d9a24b5301b5e28d01f9c061750bf39968b5cd
392 Risk Score

Malware Insights

Xls.Downloader.94c25b356b5a6cac-9978798-0 · confidence 95%

MITRE ATT&CK
T1204 Malicious Link T1204.001 Malicious Link: User Execution T1566 Phishing T1566.002 Phishing: Spearphishing Attachment T1059 Command and Scripting Interpreter T1059.005 Command and Scripting Interpreter: Visual Basic

The sample is an Excel file containing an embedded Equation Editor object that exploits CVE-2017-11882. This object contains a secondary PDF payload which, in turn, contains a direct link to a potential payload. The ClamAV detection name 'Xls.Downloader.94c25b356b5a6cac-9978798-0' and the critical heuristic firings for CVE-2017-11882 and PDF direct payload links strongly indicate a downloader functionality.

Heuristics 10

  • Equation Editor Ole10Native payload — CVE-2017-11882 critical CVE likely CVE_2017_11882_EQUATION_OLE10NATIVE
    An embedded Microsoft Equation 3.0 object (CLSID 0002CE02-0000-0000-C000-000000000046) carries an Ole10Native packager stream instead of the normal Equation Native/MTEF data. This is the weaponized Equation Editor RCE delivery shape used by CVE-2017-11882 / CVE-2018-0802 maldocs. The payload (font-record overflow + shellcode) is frequently encrypted and the stream name case-scrambled to evade scanners, but an Equation object holding an Ole10Native stream has no benign use.
  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Contains Equation Editor object — related to CVE-2017-11882 / CVE-2018-0802 exploitation, but CLSID presence alone is not the malformed MTEF exploit primitive.
  • Secondary embedded PDF body has suspicious static findings critical POLYGLOT_CHILD_PDF_STATIC_TRIAGE
    A valid PDF body was found at a nonzero offset inside another container and its carved contents matched PDF exploit or lure heuristics. This catches polyglots where the top-level magic routes to ZIP/OLE while a PDF reader or downstream parser opens the hidden PDF payload.
  • PDF link points directly to executable/archive payload critical PDF_DIRECT_PAYLOAD_LINK
    PDF contains a clickable HTTP(S) URI whose path ends in an executable, script, shortcut, disk image, or archive extension. Documents can legitimately link to installers, so this is a high-risk delivery indicator rather than a standalone exploit fingerprint.
  • ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.94c25b356b5a6cac-9978798-0
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Clickable PDF combines external action with parser-evasion structure high PDF_ACTION_PARSER_EVASION
    PDF has an external clickable URI together with object graph or xref structures that make parsers disagree, such as divergent duplicate objects, parser divergence, or xref offset mismatch. That combination is stronger than a plain link: the document is both an outward-action carrier and a parser-confusion/evasion sample.
  • VBA project contains no executable statements low OLE_VBA_MACROS
    Document contains a VBA project, but extracted modules only contain attributes/options/comments and no executable statements.
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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://https://www.google.co.in/example.com
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/

Extracted artifacts 8

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
7f506327609c082af1cd37dde23bc2c71a000f7d1ef530b6abb66775040a7673
vba-macro oletools.olevba.extract_macros (decoded VBA source) 1206 bytes
ole10native_00.bin
0a127dc5635c3aeb6adf0cc467b3ed711456227d97227139debbbc7724f45342
ole-package OLE Ole10Native stream: MBD000EE31D/Ole10nATiVe 1843 bytes
font_00_sfnt_off0000817d.bin
68d167e68895a344f3603a4efd0d8438eb8fdebe759cee48f2b4adf75c76c961
pdf-font-stream PDF embedded font (sfnt) at offset 0x817D 12100 bytes
font_01_sfnt_off00009f95.bin
50551000b9f90b3f445ee94749557d9ddf96697a74984b3ccf3d2bae66910750
pdf-font-stream PDF embedded font (sfnt) at offset 0x9F95 15820 bytes
polyglot_child_pdf_off00001000.pdf
a6fb183fd3012529f64f74e188d1daa7e35a26ca1c11bffc159fbbbe1c527552
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x1000 1093632 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off00006200.pdf
1f1dc53a2e7b9a438783dce5fa2e6dec0ee71d1b2094b15b83aa9f0bc6d189d9
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x6200 1072640 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off0000e400.pdf
640e6c1ea26d8d4046574b62858ad9e5db97176b6d60d671816e6c9d6f2e1f97
polyglot-child-pdf Secondary PDF body inside ole container at offset 0xE400 1039360 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off0002d000.pdf
036320106aa37f92f5a14cc8183dd76726d77dcfc9ded92fe830f0bedd6718fc
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x2D000 913408 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely