Malicious PDF — malware analysis report

Static analysis result for SHA-256 b351dfb9b16c98ef…

MALICIOUS

PDF

85.9 KB Created: 2021-07-01 10:20:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: af92f8ce95b9f493f2d6a8f8feb76f3b SHA-1: a18d7c10f8ca3e44e84ebb680a9d8cb0f12c41f0 SHA-256: b351dfb9b16c98ef4c0aa8b973c71a0769e0952eb1bb83870c45d4730eb83f5d
156 Risk Score

Malware Insights

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

The file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to various websites, including those hosted on compromised CMS upload directories. The document body is heavily obfuscated and unreadable, suggesting it is not intended for human consumption but rather to facilitate the distribution of malicious links.

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 http://anvlaw.com/userfiles/file/38407002781.pdf In PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/160737cb2b0a4e---80049617079.pdfIn PDF document text
    • http://rheumatology.institute/upload/content/file/julutovifakurilodus.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/19f6e222cda4af189f1e00f392c398de/nolokexov.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/290893uhqfd2ube2vgvpjddsj1/5717705442.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/1f07e59657073926873f93e234793dfa/patevizulovadupog.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/85d48d64cc7c2ba678eee3c79891ec68/37599604713.pdfIn PDF document text
    • http://aplus.to/userfiles/file/25464413518.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/8f5b9b7a77bc1e6a2cc852f333ed9db1/29783218065.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b7d2027809c---wuvabutiwitogaz.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/d4ae4840d8314f10100e644561609936/rorimamozawevafegoni.pdfIn PDF document text
    • https://bnovum.hu/downloads/53685380174.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/47236105426.pdfIn PDF document text
    • https://hssipm.com/wp-content/plugins/super-forms/uploads/php/files/cf24c4976a7a6cf645b16a7218186336/52079602615.pdfIn PDF document text
    • http://leebyunghun.kr/new/upload/board/files/sizufolodobu.pdfIn PDF document text
    • https://tecnibat.net/uploads/archivos/masasalofubodanuxejegere.pdfIn PDF document text
    • http://autodilykanka.cz/cmsimple/images/file/86636021123.pdfIn PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/ejfts3fo76km7c6e29mqbj15q5/voxategeladizofud.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086408adc298---sevixifivotojujiragukira.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609effa89442e---gusij.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/16073e52b8ee56---42914601610.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/16093aeed8b9d8---87199924415.pdfIn PDF document text
    • http://www.kickcommerce.com/userfiles/file/49583837876.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/ajn7u2a628vhgsi7m2e0ih3c7m/soxomojezubanitataguzedo.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c284a4a6225---danazakijufevofew.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=touchless+automatic+car+wash+near+mePDF 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_off0000ebda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBDA 16856 bytes
SHA-256: 3bac67295fee3731aa2ccf88bfe52971b5d2b1a0cd5b8b2bca62221a8e17a70e
font_01_sfnt_off000117e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117E3 10644 bytes
SHA-256: 638205af7aaa51abbe2eca784a011203a993dd8d4d8a4503a7674807c8884b45
font_02_sfnt_off00013029.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13029 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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