Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8f852a8b8ae3e5d…

MALICIOUS

PDF

69.9 KB Created: 2021-09-27 15:29:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 167e0221ddce22b6dc57f403a13660bb SHA-1: 83640626cba6f9f5863462ff7284f67725b84029 SHA-256: a8f852a8b8ae3e5df9a599ed8e88b2b66b8e52d65542309759d96db6a15d2a19
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which are designed as a link farm. Several heuristics indicate that these links point to compromised CMS uploads and disposable hosting, suggesting a phishing or scam campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://ketchas.ru/uplcv?utm_term=karbonn+android+game PDF link annotation
    • https://sardavetri.it/userfiles/file/65764696475.pdfIn PDF document text
    • http://akademia-jedenastka.pl/zdjecia/fck/file/kuburekewunakaki.pdfIn PDF document text
    • http://lasermedia.cn/userfiles/file/98588472883.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/161341986777ec---lutelesasavorosekuz.pdfIn PDF document text
    • http://mebelhotel.ru/images/news/file/28013061106.pdfIn PDF document text
    • https://saglamahsapkutu.com/img/editor/image/file/16322018869.pdfIn PDF document text
    • http://orderkai.com/uploads/files/91258866162.pdfIn PDF document text
    • http://ukwoodrecycling.com/userfiles/files/45300561499.pdfIn PDF document text
    • https://506hlapeta.com/files/file/xifuxididebazera.pdfIn PDF document text
    • http://vibratingsieve.com/d/files/loraratunavopavab.pdfIn PDF document text
    • http://schuetzenfest-hemeringen.de/ablage/userfiles/files/22913670142.pdfIn PDF document text
    • http://stoka-saarlouis.de/userfiles/file/14277633279.pdfIn PDF document text
    • http://baobianhkhang.com/upload/files/32562426488.pdfIn PDF document text
    • http://www.otevrenysklep.cz/ckfinder/userfiles/files/fikerixoxojuvirutuba.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161393ac0640e5---kopebewitazidal.pdfIn PDF document text
    • http://fireprovietnam.net/luutru/files/kopanawunepima.pdfIn PDF document text
    • http://rowerowaszkola.pl/imgturysta/files/14686518933.pdfIn PDF document text
    • https://esterkins.de/ckfinder/userfiles/files/48271101492.pdfIn PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/89860269610.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/161417baf86ea8---duwigagofozaromaw.pdfIn PDF document text
    • http://griesvoegwerken.nl/UserFiles/file/gepamuzozuwiminalaje.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131669293acb---xoxaguluzukivinoxu.pdfIn PDF document text
    • http://ineke-ott.nl/keramiek-beelden-imagesfile/10083900210.pdfIn PDF document text
    • https://ambient-interier.cz/files/files/fajirajokapijuviwija.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_off0000b1c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1C4 15392 bytes
SHA-256: b420f8b95552fb312bff13deaa507525873a9a7b3b080749f482d1e7edde3795
font_01_sfnt_off0000d8bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8BD 10408 bytes
SHA-256: 7c11f1d184963177d592ca8fe70c933782dff463054032b0991c4c193f1697f6
font_02_sfnt_off0000f00c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF00C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1