Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef31324e61573805…

MALICIOUS

PDF

88.2 KB Created: 2021-08-12 18:43:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: f4d291659d88ed6ed3978be9c02dc30f SHA-1: 800a859162dd037a6d41b179d59db95769e61b0c SHA-256: ef31324e61573805fac873d9a26b52e26013f64ea857ca0da7676ed9d84a1aa4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ClamAV as 'Pdf.Phishing.Trojan-d2568dad23a94d95' and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised WordPress upload storage, with many distinct hosts and URLs. The embedded URLs are likely used to redirect users to malicious sites for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9886

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://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/638b09c2e945b0a2feec4cdadfd2b0ca/kaxupexisenoka.pdf In PDF document text
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/10616abec888cfe624c9e48226ab99af/wudorizosefag.pdfIn PDF document text
    • http://tcurryproperties.com/konadnew/userfiles/file/giriv.pdfIn PDF document text
    • http://consoles-a-gagner.com/fckeditor/userfiles/file/39559579331.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/9tgshr5qubti9agjhtl38kg7kj/46279383514.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/f12ca824a641af5ca0d3bf87167b0a3a/ninuxowilozu.pdfIn PDF document text
    • http://radio-salsa.com/php/rs/filesupload/file/mowiganixuruxitumibiritoj.pdfIn PDF document text
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16087d0b87b10d---14961177639.pdfIn PDF document text
    • https://thinhtienjsc.vn/images/news/files/75810043928.pdfIn PDF document text
    • https://hobbes-group.com/upload/files/podusilaron.pdfIn PDF document text
    • http://crm333.com/documentos/file/23412885796.pdfIn PDF document text
    • https://ou-ravda.com/ckfinder/userfiles/files/9301285651.pdfIn PDF document text
    • https://foodvellythailand.com/upload/files/5615819738.pdfIn PDF document text
    • http://livelyway.com/ckfinder/userfiles/files/35188826665.pdfIn PDF document text
    • https://egyiksem.hu/uploads/file/43127401942.pdfIn PDF document text
    • http://vankouwenenmastop.nl/UserFiles/file/fatoredonaf.pdfIn PDF document text
    • http://designpavelzapletal.cz/files/file/15994803642.pdfIn PDF document text
    • http://cintabogor.com/Uploads/userfiles/files/migajekixinabenixobim.pdfIn PDF document text
    • http://skoleniridicubrno.cz/ckfinder/userfiles/files/mazojanevolabupesadesij.pdfIn PDF document text
    • https://bio-obst-und-gemuese.de/userfiles/file/zagijarik.pdfIn PDF document text
    • http://thuaphatlailongthanh.com/upload/contentFile/minhchau/file/wabanojok.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160d460658c870---42786510730.pdfIn PDF document text
    • http://munnarinfo.in/userfiles/file/zubabebisizuredefi.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/64690364153.pdfIn PDF document text
    • https://oncallanatomist.org/ckfinder/userfiles/files/vifep.pdfIn PDF document text
    • https://szekszardportal.hu/userfiles/file/64802893692.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=what+are+the+ada+guidelines+for+diabetes+screeningPDF 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_off0000f623.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF623 16184 bytes
SHA-256: 82390c0215ae073936c477427d05b12925e68a7cba2d9515f0baf9ef1d8367b1
font_01_sfnt_off00012007.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12007 10988 bytes
SHA-256: a8f17ec6bdabc0d3b48b49ac4b97064d4a45d0b590295c08005f1fe0503cb700
font_02_sfnt_off00013949.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13949 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1