Malicious PDF — malware analysis report

Static analysis result for SHA-256 e7584af8d8b345e3…

MALICIOUS

PDF

97.0 KB Created: 2021-06-26 04:47:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: f08b1c576310ac65183549dc46f67c3e SHA-1: 85eb215b059563bfbbff058ac8b606fd19cdbeb2 SHA-256: e7584af8d8b345e3594430def919145053fc08457080dba211501a6315c6f536
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Static analysis reveals it functions as a link farm, containing numerous URLs pointing to other PDF files, many hosted on potentially compromised CMS uploads. This suggests an attempt to distribute further malicious content or engage in SEO-based phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://medtek.vn/storage/file/poxiv.pdf In PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/31590336586.pdfIn PDF document text
    • https://giriconsultancy.com/content_files/files/vebamano.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085cbfe16c8e---80014842511.pdfIn PDF document text
    • http://fotografiafrancescosomma.com/userfiles/files/43929788792.pdfIn PDF document text
    • https://rintrans.com/files/nexarilupapel.pdfIn PDF document text
    • http://istrouma1971.com/clients/9/9b/9b88b062b8d6af44b28e209fcb06d7d5/File/numomet.pdfIn PDF document text
    • https://samowar.me/userfiles/files/99493440432.pdfIn PDF document text
    • http://gphs84.com/clients/866382/File/lamabiredelonudojet.pdfIn PDF document text
    • http://videoacceso.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba2f59d7dd6---feladewexopap.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/018e8080d21bfa7669a7373b9c3588eb/83769166810.pdfIn PDF document text
    • http://hongdanhaudio.com/luutru/files/nirorifisagebozajerinadu.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/160946700b70e2---94151728370.pdfIn PDF document text
    • http://afgventuregroup.com/cfiles/file/1141538592.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607162431004d---nufinodoparotawokudevan.pdfIn PDF document text
    • https://vieclambanhang247.com/upload/files/75487335501.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/b450e6edaca77327381bb5093f475fee/lotubesosigigiru.pdfIn PDF document text
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/30851fb13d05b9d3f0a4ade69d0fb21f/9364436883.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/mgn9uo4k7t8utan58mlgaehdsh/fufexobavemizagon.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/0137c034beed04637a141a4115f50fe6/tifedididoxod.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/vt1v20mudbikkhiqhg2sl9adc9/5900220350.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160983e287f64b---46725793708.pdfIn PDF document text
    • http://nacyc.jp/Upload/file/41430292351.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=environmental+impact+assessment+example+pdfPDF 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_off000119b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119B4 16636 bytes
SHA-256: 33a40c6c4498dd5f46fe59404da61fe6c5cd1e4950c6fb8d2191d4add7468c22
font_01_sfnt_off00014502.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14502 10932 bytes
SHA-256: 283003d929de39af5110525515d7523852bdc22f9e55bbd4bfd0c6d7aa9b608e
font_02_sfnt_off00015e5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15E5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1