Malicious PDF — malware analysis report

Static analysis result for SHA-256 82efcf2350d49576…

MALICIOUS

PDF

83.4 KB Created: 2021-09-08 14:51:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 3cad9c149e93fa221f1877123b648147 SHA-1: db30f543d83b85e10e0eae770578d379ca6e49b2 SHA-256: 82efcf2350d4957630a5b13aa6cedfe4b0f2039725e825b970073708972600aa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was identified as malicious by ML classifiers and ClamAV, specifically flagged as phishing and a trojan. It contains numerous embedded URLs, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of external URI heuristics and the 'PDF_SEO_DISPOSABLE_LINK_FARM' firing further support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://cbcom.eu/ressource/site-image/files/44310138007.pdf In PDF document text
    • https://grootformaatspandoeken.nl/userfiles/file/43191307307.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210902020751.pdfIn PDF document text
    • http://5m-tti.com/uploads/image/files/tegebuviwipi.pdfIn PDF document text
    • http://fine-trading-knotwork.de/uploads/media/zofaxigolegenadofijivog.pdfIn PDF document text
    • http://arcdesantmarti.com/biocop/Images/images-editor/file/84325916226.pdfIn PDF document text
    • https://shunnasato.com/zaxedosixixogejasuwovafa.pdfIn PDF document text
    • http://american-security-inc.com/assets/ckfinder/userfiles/files/vibuzubegufodulap.pdfIn PDF document text
    • http://ros.by/ckfinder/userfiles/files/71782118020.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161344b8649cd6---56376105178.pdfIn PDF document text
    • https://ylwlgwadmin.ylwl.cn/upload/files/55210315422.pdfIn PDF document text
    • http://dichvutheapec.com/upload/FCK/file/97725708955.pdfIn PDF document text
    • http://myepres.com/HotelEstimator/userfiles/file/risaw.pdfIn PDF document text
    • http://kprmk.pl/userfiles/file/85721855264.pdfIn PDF document text
    • https://pellevah.com/upload/files/74032469856.pdfIn PDF document text
    • https://broadstripe.com/wp-content/plugins/super-forms/uploads/php/files/5bbada26dc534923d9088da5c4f1a2ec/tefefafirogakemavup.pdfIn PDF document text
    • http://airsoft1.ro/files/file/90458717693.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/449b0bbac06e055c415ebbd7650acc26/38211536785.pdfIn PDF document text
    • https://coverline.ro/userfiles/file/55166746751.pdfIn PDF document text
    • https://kfmaccounting.com/webroot/img/content/files/molukirevumodidigirirol.pdfIn PDF document text
    • https://mavibusiness.it/file/2380505067.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130ad898ef6c---futeluw.pdfIn PDF document text
    • http://kidsjeodo.com/images/files/25568973283.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=philosophy+of+social+research+pdfPDF 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_off0000e32d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE32D 17108 bytes
SHA-256: 5fa16ee590eec8c842a39ac2e499fbb440295853267ed972fa02250f20de9049
font_01_sfnt_off00010f98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F98 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000127af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127AF 10632 bytes
SHA-256: fda9e9eca3ebb8532fccfe4acb368d9ac0ffa042543963bbada70ab0be692f28