Malicious PDF — malware analysis report

Static analysis result for SHA-256 d71833f348f10aca…

MALICIOUS

PDF

76.1 KB Created: 2021-09-24 15:36:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 01c71db2c7c76ab6df656b01b650149a SHA-1: 35bb1b67cddda58e900ce4668f301311a795b2f7 SHA-256: d71833f348f10aca9be8efa816a3f6d7c12203542095badf281f21932da7290a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on disposable domains or compromised WordPress installations, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to host and present these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://archism.ru/uplcv?utm_term=dizziness+upon+standing
    • http://busto-wl.gattinonimondodivacanze.it/themes/userfiles/files/xofimisatodoran.pdf
    • http://www.peritaonline.es/ckfinder/userfiles/files/doxijerilagajo.pdf
    • https://svltv.in/userfiles/files/fewulode.pdf
    • http://goodfortune.hk/UpLoadFile/file///mibapodofebosubenop.pdf
    • http://fuerst-architects.com/uploads/file/94980236963.pdf
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/02dfa0ea68fb9780d2b637244636998b/xisevunegofusovorik.pdf
    • http://zjnep.com/ckeditor/ckfinder/userfiles/files/xonavukopoli.pdf
    • https://faktxeber.com/resimler/files/debigefajewigotufidike.pdf
    • http://rsst77.ru/upload/files/77927436289.pdf
    • https://sakura-bashi.com/uploads/files/202109050112203252.pdf
    • https://digbijoynath.in/uploads/userfiles/files/43692191425.pdf
    • http://poetische-malerei.de/web/editor/files/judopil.pdf
    • http://www.gieskestukadoors.nl/ckfinder/files/files/zukujademorife.pdf
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612ffce840ae8---wiladulajada.pdf
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161492662e232a---75666461371.pdf
    • http://longarmquiltingacadamy.com/fckeditor/userfiles/file/21137579984.pdf
    • https://korzayithalat.com/spot/admin/fckeditor/userfiles/file/vokirogezukotopuvo.pdf
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b2d3c26135---88739248495.pdf
    • http://cncforginghammer.com/d/files/delotulaluganeb.pdf
    • https://tutorsbureau.net/userfiles/file/71265328914.pdf
    • http://hurtglass.pl/upload/file/46774900994.pdf
    • https://universitecentrale.net/uploads/FCK_files/file/tepisujinekij.pdf
    • http://alatheir.com/atheirwsfiles/file/jakigavamuzid.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c2c4.bin
85c5283bac0e3238cedbda4d6717f7db6038a6e832a9e1f3255e74bc7afc03ad
pdf-font-stream PDF embedded font (sfnt) at offset 0xC2C4 18420 bytes
font_01_sfnt_off0000f276.bin
205c10e3c6487a16799a795700fb8d766ca7ef1ff05da308230278d830b41c23
pdf-font-stream PDF embedded font (sfnt) at offset 0xF276 10580 bytes
font_02_sfnt_off00010a90.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A90 16792 bytes