Malicious PDF — malware analysis report

Static analysis result for SHA-256 8458e296e06403dc…

MALICIOUS

PDF

78.3 KB Created: 2021-09-12 22:23:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: c7eac10ea34662c90597f78668ae7aa9 SHA-1: d9eacdac9b267c45ff769b26ffe008f41b77c2d3 SHA-256: 8458e296e06403dcf5cc4d6bca73e4652ef8db3c4952eb303f3fc9de7c835080
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of links pointing to various domains, many of which appear to be compromised CMS upload directories. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this PDF is part of a link farm designed to distribute further malicious content. No scripts were extracted, but the structure itself is indicative of a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://akproauto.com/nbloom/fckuploads/file/kigakukasemakamusezag.pdf In PDF document text
    • https://www.multilandtours.com/assets/ckfinder/userfiles/files/retujisumavamuxalapuzuw.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-12/20210912171816606442.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613c8c3c14ccf---bokumakepujonebakugogub.pdfIn PDF document text
    • http://4x4autok.hu/userfiles/files/49957247797.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/161331713d7e2f---45832642241.pdfIn PDF document text
    • http://dealershop.es/userfiles/file/zovudopuwifofuwuneviw.pdfIn PDF document text
    • https://vhssirimpanam.org/ckfinder/userfiles/files/xifosavonexus.pdfIn PDF document text
    • http://langfordfinancialservices.com/userfiles/files/kabiritemalefotutisulave.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/0frq87kfjdfcr0lv7390p3h4po/lubitokomed.pdfIn PDF document text
    • https://morabia.fi/images/file/79523872038.pdfIn PDF document text
    • https://dom4m.de/userfiles/files/91472314559.pdfIn PDF document text
    • http://huynhgiabaohotel.com/uploads/FCK/file/78673375650.pdfIn PDF document text
    • https://bimetoor.com/basefile/bimetoorir/files/17169436487.pdfIn PDF document text
    • http://memsports.com.br/admin/libs/ckeditor/ckfinder/files/mapesedazazosora.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138356b22b0e---964541196.pdfIn PDF document text
    • https://opsclown.it/ckfinder/userfiles/files/takaka.pdfIn PDF document text
    • http://balie.overeembv-profielen.nl/upload/files/44891446165.pdfIn PDF document text
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/vudupas.pdfIn PDF document text
    • http://stilistspb.online/public/files/uploads/files/kirag.pdfIn PDF document text
    • http://jagdrevier.hu/upload/images/file/dibifipamovivuxag.pdfIn PDF document text
    • http://pcwenhua.com/uploadimg/file/16306510021401071252.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=android+scale+image+to+fit+screen+widthPDF 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_off0000cc9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC9A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e4b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4B1 10988 bytes
SHA-256: d4e774d97d8b3ecd028739da49f945e73fa541cdef49c9fcca70faead3dd5e12
font_02_sfnt_off0000fdea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDEA 17472 bytes
SHA-256: e58cc67e319d603461c2571df89c706bbcb1b3577f0a47973b330f9347671949