Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ff89915814d3774…

MALICIOUS

PDF

77.8 KB Created: 2021-11-02 00:55:47 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 3640114863e5af8b752612e3e52ea40a SHA-1: aa5b9df01045e2fba8adc1507c7eb03f35d6c0ae SHA-256: 8ff89915814d37741a754b43efde9aa5a0be371082c79e5337fd257840a478ae
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The `wkhtmltopdf` authoring application is noted, but no specific exploit or script was identified within the provided evidence.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://infrive.ru/uplcv?utm_term=where+is+area+code+817+from PDF link annotation
    • http://meuble-tunisie.com/userfiles/file/4826559949.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fa6e3c33da---sefidurimofalodoba.pdfIn PDF document text
    • http://keralabiblesociety.com/fck_uploads/file/bozigovot.pdfIn PDF document text
    • https://nacionalequipamentos.com/ckeditor/uploads/files/mefuwesugimoz.pdfIn PDF document text
    • http://masterkontroll.hu/ckfinder/userfiles/files/55497056224.pdfIn PDF document text
    • http://rc-modeller.se/images/file///62765824369.pdfIn PDF document text
    • https://mallncart.com/userfiles/files/tukexol.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/e8oo5fa87nb18c58r3jfim60v7/82443215620.pdfIn PDF document text
    • https://vestol.bg/files/file/nemegefebituvolufuxamujur.pdfIn PDF document text
    • http://burelomdo.com/ckfinder/userfiles/files/wogefu.pdfIn PDF document text
    • http://saltokisport.com/uploads/files/biretavafawa.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/dukujaripexodijusagafuxuk.pdfIn PDF document text
    • http://artattack-concerts.de/files/file/pumulimupatom.pdfIn PDF document text
    • http://inspeq.eu/public/files/datovivi.pdfIn PDF document text
    • http://autosvilar.com/uploads/ckfinder/files/gonizepubab.pdfIn PDF document text
    • https://celebicatering.com/upload/ckfinder/files/45679246840.pdfIn PDF document text
    • http://flomojapan.com/upload/files/2928996731.pdfIn PDF document text
    • http://demirlermetal.com/resimler/files/6028341074.pdfIn PDF document text
    • https://lean-ds.com/upload/editor/file/fijawojubetifafu.pdfIn PDF document text
    • http://savages.lu/imagesRTE/files/10718028839.pdfIn PDF document text
    • http://pb-book.com/user_file/file/masaduzijok.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1617af173a4660---xinik.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_off0000cc68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC68 16880 bytes
SHA-256: a1560426d85d326494b0aefd5dc237b8c84815efb847b8d2ae54af8d10071e13
font_01_sfnt_off0000f88c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF88C 10796 bytes
SHA-256: cbed514b07111cc020eecbce62b4aef0d12d8147ea305687114eb1136e2052a0
font_02_sfnt_off00011192.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11192 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1