Malicious PDF — malware analysis report

Static analysis result for SHA-256 815d4d3cec3dbe73…

MALICIOUS

PDF

72.6 KB Created: 2021-09-24 16:18:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c78b9cc2e4cc057aec02e0190b2cc1fa SHA-1: 390ea72f055928a4d8912ba489329b01436e92ce SHA-256: 815d4d3cec3dbe73eb31cd9537ecbd153893c7271c08589b18b6b4e9657cee67
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Numerous embedded URLs point to compromised websites and link farms, suggesting a phishing or malware distribution campaign. The presence of PDF-specific heuristics related to URI and link farms further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://huntic.ru/uplcv?utm_term=how+can+i+share+app+through+bluetooth PDF link annotation
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/161376e2121910---senolavubupezusonakasuxi.pdfIn PDF document text
    • http://khacvietlaser.vn/public/images_news/files/taxoxevagepi.pdfIn PDF document text
    • http://gardena.crazyrockinsushi.com/uploads/files/buwuvanorekisezevamiba.pdfIn PDF document text
    • http://vp-dmsh.ru/admin/ckfinder/userfiles/files/tulod.pdfIn PDF document text
    • http://cabinet-blin.fr/ressource/site-image/files/goxuk.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/rujunidifuxawigivozederu.pdfIn PDF document text
    • http://maybaobidinhdinh.com/upload/files/pufur.pdfIn PDF document text
    • https://drrajanmahtani.com/userfiles/files/vuborexu.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b744540725---podeluzufu.pdfIn PDF document text
    • https://srmhomes.com/images/bulk_images/files/varuzofetodegexutup.pdfIn PDF document text
    • https://saksisan.com/upload/ckfinder/files/26959709345.pdfIn PDF document text
    • http://fpole.ru/sadm_files/46241399167.pdfIn PDF document text
    • http://eiak.org/upload/editor/files/fupaniwuxiziwepudoza.pdfIn PDF document text
    • http://33podarka.ru/pictures/files/xapepogilovilew.pdfIn PDF document text
    • http://cgpreceptor.com/ckfinder/userfiles/files/lizemowebadezufiju.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ca66032290---13017296379.pdfIn PDF document text
    • http://datacomsystems.cz/userfiles/file/mowosidenofasi.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/116695c9c3df8b905ee9cc8ebf85a137/sunajatiruvaj.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/265ad1c724fbf1e91e3c0b577abf18e4/jenufodetekamapili.pdfIn PDF document text
    • https://jvlegacyhomerepairsmd.com/nbloom/fckuploads/file/24427510329.pdfIn PDF document text
    • http://vetusmeter.com/images/upload/File/80723320129.pdfIn PDF document text
    • http://www.donboscovizag.org/images/files/mosedusowatudezok.pdfIn PDF document text
    • http://gptools.net/userfiles/file/36607939110.pdfIn PDF document text
    • 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_off0000b6dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ceee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEEE 17596 bytes
SHA-256: e9d1e6155c98f6cef63eaa11c67b03ff2e74bfc404ac56cc689b678563d03bc2
font_02_sfnt_off0000fb63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB63 10968 bytes
SHA-256: 78706e9f25b933e45ffe28081883f2ecbd40ef067b7d7fab99f3f789e3978726