Malicious PDF — malware analysis report

Static analysis result for SHA-256 f92ec630cbedb907…

MALICIOUS

PDF

88.9 KB Created: 2021-09-08 20:53:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 493813a2642fe59226e547bc69b7a950 SHA-1: cd2112e1efb1034fe8cf5b2d03ffae03d9c0ca6a SHA-256: f92ec630cbedb90784757f321fa5c3f249e8b8cc9951a9b571b0a0c9e81d5f1d
156 Risk Score

Malware Insights

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

The sample is a PDF document identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or are hosted on disposable domains, indicating a link farm for SEO poisoning or phishing. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically flags this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://snieznik.pl/userfiles/file/vafivobakoji.pdf In PDF document text
    • http://schokoladenfontaene.de/idata/pamoritofawemesixolabuw.pdfIn PDF document text
    • http://nirmalamathachurch.org/cms_uploads/image/file/59415826672.pdfIn PDF document text
    • https://www.weboonline.com/ckfinder/userfiles/files/40016121782.pdfIn PDF document text
    • https://basisnomor.com/contents/files/jolosinovo.pdfIn PDF document text
    • https://quangcaowebsitecomvn.xemlaco.com/uploads/files/90717246433.pdfIn PDF document text
    • https://blsautomation.com/ckfinder/userfiles/files/xiram.pdfIn PDF document text
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/12112074033.pdfIn PDF document text
    • https://jcmimoveis.com/userfiles/file/muxebe.pdfIn PDF document text
    • https://vrrc.heart.net.tw/ckfinder/ckfiles/files/85984389406.pdfIn PDF document text
    • http://srilakshmienterprises.net/uploads/kixejimezuli.pdfIn PDF document text
    • http://gidaero.com/upload/fckeditor/file/ruvilumovedu.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137482963a88---xevikosugurisukajama.pdfIn PDF document text
    • https://movimientofamiliadejesus.com/images/uploaded/file/kubesutibufogiremajabe.pdfIn PDF document text
    • http://bulk-supplies.com/userfiles/file/87467439786.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132c7944ebd2---60818660806.pdfIn PDF document text
    • http://zssadkowice.pl/pliki/xuzof.pdfIn PDF document text
    • http://alles-vom-schreiner.de/userfiles/file/66148723353.pdfIn PDF document text
    • https://ecowaytechnologies.com/ckfinder/userfiles/files/39421449984.pdfIn PDF document text
    • https://commonwealthsportsawards.com/userfiles/file/vunatamaxodufuraturo.pdfIn PDF document text
    • https://royal-art.pl/uploads/userfiles/files/topelujivufosasodina.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16134161cd4a4f---68689822309.pdfIn PDF document text
    • http://elfuklid.cz/foto/Image/file/59829418342.pdfIn PDF document text
    • http://ebonit.light.bg/includes/libs/ckfinder/userfiles/files/84361151301.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/2421asu2gdsijvkdv3n1jmphk2/pudejupijidenisifomapa.pdfIn PDF document text
    • http://abbeloosschinkels.be/userfiles/file/34735870057.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=english+communication+skills+mcq+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_off0000f790.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF790 11156 bytes
SHA-256: 2061380f57fd3a185147192667e61a45e39743b301f7bce02273e4b19d530510
font_01_sfnt_off000110ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000128ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128FF 17116 bytes
SHA-256: e0eb90302b26225226dbb157d54eb7161a9e930239740dc847f3053f4dd6a690