Malicious PDF — malware analysis report

Static analysis result for SHA-256 91b884650803ae9c…

MALICIOUS

PDF

80.9 KB Created: 2021-10-14 14:06:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-03
MD5: 30e0dbf7abecf7f8b1b7db48da20465d SHA-1: 0f20a03a1614781761e20497c39e087088c39ab1 SHA-256: 91b884650803ae9c18900cbab360e06391a603e7149372aa9b15c13c00a28122
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a link farm with numerous URLs pointing to various domains, many of which appear to be compromised or disposable hosting. The ML classifier strongly indicated maliciousness, and the presence of a link farm on compromised CMS upload storage suggests an attempt to distribute malicious content or manipulate search engine results. No scripts were extracted, but the structure and URL patterns are indicative of a phishing or SEO poisoning campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://maisonforville.be/documents/file/19222349393.pdf In PDF document text
    • http://ihanzao.com/userfiles/file/20210919151157_785287547.pdfIn PDF document text
    • http://www.specemc.ru/upload/files/70528429120.pdfIn PDF document text
    • http://www.motionmantra.com/userfiles/files/80397125032.pdfIn PDF document text
    • https://sardiniagreencoast.com/userfiles/file/8187351725.pdfIn PDF document text
    • http://eecca.stocker-development.com/uploads/ckfinder/files/jarixidimejur.pdfIn PDF document text
    • http://nattuvaartha.com/assets/ckfinder/core/connector/php/uploads/files/vitoravas.pdfIn PDF document text
    • http://baharev76.ru/userfiles/file/59875126911.pdfIn PDF document text
    • https://ocloud.millionserenity.com/images/upload/files/pukonin.pdfIn PDF document text
    • http://forma8.kz/ckfinder/userfiles/files/relubikolexivotikonu.pdfIn PDF document text
    • http://xn--80aesyq.xn--p1acf/files/file/58868436041.pdfIn PDF document text
    • https://buildingexpertsdirectory.com/ckfinder/userfiles/files/55046024890.pdfIn PDF document text
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e0a4ab307b---35998423234.pdfIn PDF document text
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/70957882877.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/2facd045cc4a630f03630afd28de437b/76236420556.pdfIn PDF document text
    • http://lollanaclinic.com/image/upload/File/dunupebebibiten.pdfIn PDF document text
    • http://ritadas.in/userfiles/file/45822098639.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/860d8eaef2d6c1db7e80bc461eefb58d/wepalumubebaxetej.pdfIn PDF document text
    • http://hcm-invoice.vn/hinhanh_fckeditor/file/63530287105.pdfIn PDF document text
    • http://wawa757.com/uploads/files/46106533014.pdfIn PDF document text
    • https://bilegt.mn/userfiles/files/33895981670.pdfIn PDF document text
    • http://oodow.cn/upload/file/211009163335763589ggzgz4dh645p.pdfIn PDF document text
    • https://joebalogh.ro/imagini_ws/28540275252.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/vItLtdF7Pec/uplcv?utm_term=what+does+5+quarts+equalPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dae7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAE7 10520 bytes
SHA-256: 63b7e3528f670fbddcdbeeb2b13d5fd9331d616932f80c9e305d39d077b6d7a3
font_01_sfnt_off0000f2e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010af9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF9 16576 bytes
SHA-256: fe663415c5969b158085e79d4ab4e093016824accec5e729cf7fb481527635d3