Malicious PDF — malware analysis report

Static analysis result for SHA-256 3539182d6a01d171…

MALICIOUS

PDF

72.0 KB Created: 2021-09-26 10:49:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: caa382afbadfa9cbb558a42ddef326de SHA-1: 8f5d33be0db9030324c8c5b1e03a0726ab97fe5f SHA-256: 3539182d6a01d1717391e9c59558b42f1775784c31ae3b73a0ce044f936adaf8
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to other PDF files, indicating a link farm designed to redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this is a tactic for distributing malicious content or conducting phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://longarmquiltacademy.net/fckeditor/userfiles/file/40262473599.pdf In PDF document text
    • http://ancheng-medical.com/uploadfile/files/bemurejironoger.pdfIn PDF document text
    • http://studiobaliva.eu/userfiles/files/nizotidikizusuwonazu.pdfIn PDF document text
    • http://www.gdchgs.com/admin/img/files/tasapegokonuxarugufa.pdfIn PDF document text
    • http://megaprestige.ru/uploads/files/70363089651.pdfIn PDF document text
    • http://nemochem.cn/upload/files/49288538461.pdfIn PDF document text
    • http://mbfeed.vn/upload/files/deriwakeliribabapenejoxo.pdfIn PDF document text
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/d13a9817dc2bf92ed23f4373f30b80b6/38753256313.pdfIn PDF document text
    • http://emanuelmlevin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vujojufefutunivuwilepovof.pdfIn PDF document text
    • http://ivepe-elearning.gr/assets/UserFiles/mainHome/file/43311126375.pdfIn PDF document text
    • http://mim2010.ru/userfiles/file/pakovoweka.pdfIn PDF document text
    • http://santa.sg/images/users/00000000/files/dasamap.pdfIn PDF document text
    • https://ubitanduk.com/contents/files/fulakusurom.pdfIn PDF document text
    • http://mapect.com/upload/fckeditor/file/zitematunuvumofit.pdfIn PDF document text
    • https://pinkrali.com/calisma2/files/uploads/84867550212.pdfIn PDF document text
    • http://thietkevang.com/upload/files/97704562336.pdfIn PDF document text
    • https://www.poole.ed.jp/system/ckfinder/userfiles/files/53149234979.pdfIn PDF document text
    • http://dpsszczytno.pl/photo/file/21360240836.pdfIn PDF document text
    • http://gcoekmr.org/cukashmir/User_Files/imagefile/98237635756.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/dubobimuwubi.pdfIn PDF document text
    • https://mhreng.com/userfiles/file/pesugivajifagopetidizon.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148fa5f6f307---xinijolirok.pdfIn PDF document text
    • https://restavracia02.com/userfiles/file/dipaxogifukaxezorefoju.pdfIn PDF document text
    • http://phutungotodungha.com/img/files/18369416941.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.com/filespath/files/20210908134458.pdfIn PDF document text
    • https://maria-galland.ru/files/file/zuzubekokolofetuto.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=clear+cache+on+android+chromePDF 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_off0000b7d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7D0 10400 bytes
SHA-256: 3d44b33afd17c0348b012443c94a928cf829a8820beed89aad24f915d389fc08
font_01_sfnt_off0000cf10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF10 16876 bytes
SHA-256: 7241a955768e02a305b360bb98f696b44020cda9454b98b2fe22f512eb6d0a8c
font_02_sfnt_off0000f9db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1