Malicious PDF — malware analysis report

Static analysis result for SHA-256 4943a40d902d4b10…

MALICIOUS

PDF

94.7 KB Created: 2021-06-27 23:54:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 267aacaec8824fbbe375f0411e9c6add SHA-1: bc15637b67872948892a9762669ebe7563ff5787 SHA-256: 4943a40d902d4b1058ec0bd028fd6e435cfb366630a2294173dcb8672203a1b5
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV and an ML classifier as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS upload directories. The document body is heavily obfuscated and unreadable, suggesting it is not intended for human consumption but rather to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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 http://caryhigh1987.com/clients/41333/File/24595325645.pdf
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/160845ed3802be---pujijozujolesiwi.pdf
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9a231da7b---78145865796.pdf
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095efd388712---62575256940.pdf
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090586aa1de9---wakadovinev.pdf
    • http://alkanboya.com/files/file///tewutezekokijixejufoneto.pdf
    • http://ytlcases.com/userfiles/file/xikujoka.pdf
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/160cf8867e3ea4---4848302373.pdf
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/16074acc352bca---kudevobapezezapo.pdf
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/pnh1p0d4euikc8s7ppdbgfv0l3/25414692110.pdf
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/160beda38e4852---buniludanazitalebe.pdf
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/20e34ca69414dbb888d6a40145d216b6/defokanukusetagobega.pdf
    • http://rockpapersun.com/upload_mce_image/file/bidikefupefilokasibalom.pdf
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d54337d9c57---32183672748.pdf
    • http://accessiblevehicleservices.com/userfiles/file/petemunafopabupo.pdf
    • https://almoheetmanpower.com/public_html/userfiles/file/xipulegeb.pdf
    • http://wagnerpc.com/userfiles/files/71844210257.pdf
    • https://vishalahospitality.com/ckfinder/userfiles/files/saxamuji.pdf
    • http://workcoop.org/fckeditor/userimages/file/20210611032306.pdf
    • https://asiaviews.org/wp-content/plugins/super-forms/uploads/php/files/loicu5ro4i6c7ia707hodp2q92/zakipin.pdf
    • http://xn--e1aaafipco3bk8gra3b.xn--p1ai/upload_picture/file/fujumolepuzoxajej.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=jokes+about+gay+people
    • 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_off000110ef.bin
6965bf62750f4c85f36f8a804cff7548df940ddcc027339cd08dc394779b2207
pdf-font-stream PDF embedded font (sfnt) at offset 0x110EF 17324 bytes
font_01_sfnt_off00013de4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13DE4 16792 bytes
font_02_sfnt_off000155fb.bin
f3a553bcc8e41c9d21cf49787298a44c5f0dd3afae9e950c01e35aa77638cfeb
pdf-font-stream PDF embedded font (sfnt) at offset 0x155FB 10568 bytes