Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ae1f17dd4b0637…

MALICIOUS

PDF

72.3 KB Created: 2021-09-16 16:48:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: aa22d50b0a2749a9f74190f3ec01d324 SHA-1: de75c2389fd7ffee637910a73495d4b6ebb6612a SHA-256: 81ae1f17dd4b0637291efb3dd6da7e415472f261775aec0a0092e91f095fa3fb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous embedded URLs pointing to compromised websites and disposable hosting, suggesting a phishing or malware distribution scheme. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' indicates a deliberate attempt to leverage these sites for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://infrive.ru/uplcv?utm_term=android+means+in+tamil PDF link annotation
    • http://skpizzasubs.com/uploads/files/17360268759.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1613f933741e9e---18619575537.pdfIn PDF document text
    • http://conditum.nl/userfiles/file/93091244870.pdfIn PDF document text
    • https://onlinendttraining.com/files/rinumobaxixadosebimo.pdfIn PDF document text
    • https://maytinhdalat.vn/images/uploads/files/govutina.pdfIn PDF document text
    • https://saatyapi.com/upload/ckfinder/files/saxunalabolalom.pdfIn PDF document text
    • http://lesbambousbleus.fr/ckeditor/upload/files/gusewukojosu.pdfIn PDF document text
    • http://unityproductions.com/upload/files/momesimatuvowuzo.pdfIn PDF document text
    • http://abwingssuffolk2.com/uploads/files/85648226232.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd1cd50347---vupumojidal.pdfIn PDF document text
    • https://idea-web.ro/app/webroot/files/userfiles/files/wevomodolug.pdfIn PDF document text
    • https://varbackaforskola.se/ckfinder/userfiles/files/56814679385.pdfIn PDF document text
    • https://lapakunited.com/contents/files/30402602724.pdfIn PDF document text
    • http://rexant.by/upload/editor/files/vemumebasoxolujeve.pdfIn PDF document text
    • http://generoussecurity.com/uploads/tabig.pdfIn PDF document text
    • http://igs.compcierge-asia.com/ckfinder/userfiles/files/4325058154.pdfIn PDF document text
    • http://e3edu.vn/public/ckfinder/core/connector/php/connector.phppublic/uploadsfiles/98313561040.pdfIn PDF document text
    • http://sztarmedia.hu/_user/file/2754894728.pdfIn PDF document text
    • http://med-os.com/user_upload/file/tegej.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/c966ffca37bd5976c0f3ed81ac1ba8b5/runuvutimizuzomise.pdfIn PDF document text
    • http://administratieindex.nl/images/uploads/dufosovuvemefuruzaper.pdfIn PDF document text
    • https://heritagecambodiatravel.com/userfiles/file/86964818338.pdfIn PDF document text
    • https://www.terraton.com.my/ckfinder/userfiles/files/fenidosisifexaxo.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_off0000b81d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB81D 16972 bytes
SHA-256: 7f983a06566c2a8aca0659a67a8a97a1ad550980f9368da1d87e6e688a1f7633
font_01_sfnt_off0000e3d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3D4 10392 bytes
SHA-256: 8e6c959a77b3332676dd2b358c0e93e48c33a2db4b5ead9d3f75c9fe67064975
font_02_sfnt_off0000fb53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB53 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1