Malicious PDF — malware analysis report

Static analysis result for SHA-256 a33868847160b0b4…

MALICIOUS

PDF

71.9 KB Created: 2021-09-25 06:19:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: dd0db40058c7dc922f0b6490eeac3833 SHA-1: 6724778e93b738d7ba56245077a51353cc1c9ea1 SHA-256: a33868847160b0b47bc3d2cf44487e731b35ca112ba6acc2b6b4fc2eff7a4915
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm hosted on compromised WordPress sites, pointing to numerous PDF files. While no scripts were extracted, the presence of these links suggests an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614572da9e848---zufid.pdf In PDF document text
    • http://bantinnhadat.com/users/files/63828715495.pdfIn PDF document text
    • https://songhong-thudo.com/img/files/84764185628.pdfIn PDF document text
    • http://apismorava.eu/docs/77680030923.pdfIn PDF document text
    • http://mutamobilya.com/images_upload/files/60631293361.pdfIn PDF document text
    • https://nothingbutsafetyglasses.com/userfiles/file/32563702856.pdfIn PDF document text
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614654d3c65db---dadexafolavujibol.pdfIn PDF document text
    • http://www.andreapondika.cz/file/sevezuf.pdfIn PDF document text
    • http://clairvoyantinfotech.com/demo/images/32974514356.pdfIn PDF document text
    • https://hoangvan.vn/wp-content/uploads/files/63453149004.pdfIn PDF document text
    • http://naturpix.ch/cmsimages/file/93270846029.pdfIn PDF document text
    • http://utcsp2.rustyramone.com/uploads/files/kodasiguni.pdfIn PDF document text
    • https://okazdedziecko.pl/_files/Media/file/77403846095.pdfIn PDF document text
    • http://babamoleskine.com/files/file/4084592566.pdfIn PDF document text
    • http://www.tractortools.cz/ckfinder/userfiles/files/viwelaj.pdfIn PDF document text
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613904f94bc1b---52743993938.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/f06b04535624fe164df70f2de0641754/92235306229.pdfIn PDF document text
    • https://tanhaithanhvalves.com/quangcao/admin/file/remozozazunadole.pdfIn PDF document text
    • http://charontrade.hu/data/file/mowufege.pdfIn PDF document text
    • http://inbiosa.eu/static/cfiles/files/tekulunulezoxi.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b53c74c825---82160337350.pdfIn PDF document text
    • https://turismo-galicia.es/ckfinder/userfiles/files/81376158547.pdfIn PDF document text
    • https://aecvfcom.nrgence.com/upload/userfiles/files/70584213503.pdfIn PDF document text
    • http://ikhmongol.mn/ckfinder/userfiles/files/18013435865.pdfIn PDF document text
    • https://ratodua.com/contents/files/zewisasijuzemuxozex.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=sulthan+tamil+online+moviePDF 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_off0000b504.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB504 10348 bytes
SHA-256: 558cc94628e2858a4c9974d29193bb0741c2d4e4351c7b5b01d3b62efbb091a7
font_01_sfnt_off0000cc34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC34 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e446.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE446 17708 bytes
SHA-256: 8873fa7eaa0a6f94b59c26650c19536e0656eea9fc8c8fe41eb12c9fdf84308e