Malicious PDF — malware analysis report

Static analysis result for SHA-256 36a3c889f6a886a1…

MALICIOUS

PDF

88.7 KB Created: 2021-09-17 15:02:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d2c6b537690528527cfd0b3d1da0e6a8 SHA-1: 7594667ef0ee3b62e4e0e4b9d08583b161cdc000 SHA-256: 36a3c889f6a886a1e6074d1af4d15deccdead1c7877215004cbd55de176ad220
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that form a link farm, directing users to potentially compromised websites. Heuristics indicate these links are used for SEO manipulation and point to disposable or compromised hosting, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://coretry.ru/uplcv?utm_term=megaman+pet+android PDF link annotation
    • http://candleelectricals.com/uploaded_files/userfiles/files/79711666470.pdfIn PDF document text
    • http://lepal.sk/ckfinder/userfiles/files/6620577413.pdfIn PDF document text
    • http://preciz.com/uploads/wysiwyg/files/48598026158.pdfIn PDF document text
    • http://parmalab.it/userfiles/files/73694165594.pdfIn PDF document text
    • https://www.theknowledgeonline.com/files/lib/ckfinder/userfiles/files/90439027610.pdfIn PDF document text
    • http://sushiloverca.com/uploads/files/limovitawud.pdfIn PDF document text
    • http://cosmoscm.com/contents/files/24129556833.pdfIn PDF document text
    • http://kondicionery-elektrostal.ru/upload_picture/file/zaludarenitabonefanidi.pdfIn PDF document text
    • http://tiquital.com/documentos/file/67869322463.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161371875897bd---83802724629.pdfIn PDF document text
    • https://itandem.net/ckfinder/userfiles/files/fojuwomajuxoxotaz.pdfIn PDF document text
    • https://amursvoidom.ru/media/files/xakuxogosatogenapime.pdfIn PDF document text
    • https://szalkasszorutacskok.hu/app/webroot/files/content/files/zeveki.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eec1c17b2c---lidodiwu.pdfIn PDF document text
    • http://ride-on-earth.com/images/blog/file/kadex.pdfIn PDF document text
    • http://scales-center.com/shop/fck_file/file/7555381567.pdfIn PDF document text
    • http://www.gpkoaee.ru/ckfinder/userfiles/files/patoroluwepaf.pdfIn PDF document text
    • http://lianbang123.com/uploads/files/202109090349539535.pdfIn PDF document text
    • https://maydangson.com/vietkiendo/upload/file/8751803166.pdfIn PDF document text
    • https://bluetact.com/ckfinder/userfiles/files/kobajosojemupo.pdfIn PDF document text
    • https://0a3exp.com/upfiles/editor/files/wunekerilekavifom.pdfIn PDF document text
    • https://esterkins.de/ckfinder/userfiles/files/62629510906.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/16131979a8d30e---61736802094.pdfIn PDF document text
    • http://cuacuonnhaxuongbinhduong.com/upload/files/61040983103.pdfIn PDF document text
    • http://k-sta.kr/FileData/ckfinder/files/20210907_4A3DFCA7C6296065.pdfIn PDF document text
    • http://samtekelektrik.com/files/13601148234.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_off0000f058.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF058 20400 bytes
SHA-256: 2a38d421acd472a5dc909f2a9bd4a4fe1b3caf9a7a78aed7c491b9236048d5a5
font_01_sfnt_off0001259a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1259A 10516 bytes
SHA-256: d085ed387dd35c9f5d82c944dff0539d8c5b657ef98c647fd1605eb36760dd44
font_02_sfnt_off00013d40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D40 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1