Malicious PDF — malware analysis report

Static analysis result for SHA-256 83b4c75de929b11f…

MALICIOUS

PDF

71.4 KB Created: 2021-09-25 20:08:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5334b35e4ce18b2bee96b03f11c4d9ae SHA-1: 6ad41588ccec32f240e1ea60321a3d194faeec25 SHA-256: 83b4c75de929b11ff533533d833793db1a0b851c9c264c103ae0c1a8579c604a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The presence of 'utm_term' parameters suggests a link farm designed to drive traffic, likely for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://nomylo.ru/uplcv?utm_term=clash+of+clans+offline+mod+apk+download PDF link annotation
    • https://berettyotv.hu/userfiles/files/60171478262.pdfIn PDF document text
    • https://www.benkorner.nl/admin/library/ckfinder/userfiles/files/14514097269.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613a178df255f---zabavazobojovugamasenogi.pdfIn PDF document text
    • https://cungcapthitdetuoi.com/app/webroot/files/images/pages/files/jigofagetetanifapok.pdfIn PDF document text
    • https://kvzriu.org/images/file/gowapep.pdfIn PDF document text
    • https://kangaroovietuc.vn/webroot/img/files/62643956314.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/f2547539b2bf430d35bde2a1fe9e6488/22101424636.pdfIn PDF document text
    • http://unseenadventure.com/userfiles/file/rasuvu.pdfIn PDF document text
    • http://radioevangilereal.com/assets/ckfinder/core/connector/php/uploads/files/16463099926.pdfIn PDF document text
    • http://medicare-darmstadt.de/bilder/UserImages/file/vujiremux.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143ff0d41786---dipelusuwepigafenivepavid.pdfIn PDF document text
    • http://lexxyin.net/files/fckeditor/file/82504665580.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109251620389880.pdfIn PDF document text
    • http://duythuc-bearing.vn/uploads/userfiles/file/94272152646.pdfIn PDF document text
    • http://corporatiegids.nl/uploads/files/zamubumiwavusaxatopem.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/670197b7c235951b8361458028c77d95/6581506366.pdfIn PDF document text
    • http://villkasz.hu/editor_up/3258243276.pdfIn PDF document text
    • http://www.bordadoindustrial.com/ckfinder/userfiles/files/30760941232.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf33a2e431---54007698961.pdfIn PDF document text
    • http://ekotop.eu/userfiles/file/12864759102.pdfIn PDF document text
    • https://dolaodong.com/userfiles/file/41623000589.pdfIn PDF document text
    • http://sklepjola.pl/userfiles/file/16694536348.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_off0000b17a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB17A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c991.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC991 10896 bytes
SHA-256: f11b08d6d2a654c6a0de3d24c27fdb9721095b36557cdfcaa4d6f9f3e775bd79
font_02_sfnt_off0000e29d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE29D 17780 bytes
SHA-256: 51947693d4f7002dd892ed91b6a3013f440cae283b4b08a89eb1dedc3eef905c