Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac81b0cdcb88883c…

MALICIOUS

PDF

81.4 KB Created: 2021-09-08 01:54:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f4e3635309d6e977b10bcf5d47825a28 SHA-1: edabe19e51fef84e5b3a6fc3556757a6fecb99db SHA-256: ac81b0cdcb88883c0b826f9c948f688bb3752687b63661176e577e9d859316e6
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document that contains numerous links pointing to compromised WordPress sites and disposable hosting domains, likely intended to trick users into downloading further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan. Although no scripts were explicitly extracted, the PDF structure and URI heuristics suggest it functions as a downloader or redirector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://philabc.ru/uplcv?utm_term=andaman+nicobar+map+pdf PDF link annotation
    • http://79.170.40.182/boothtastic.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a74d01f223---57728675237.pdfPDF link annotation
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/9816a88392b206b6ca78a474b031e915/73048421515.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/pivopugosujazaxi.pdfIn PDF document text
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086c9eba8d73---24655912139.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ab5bbda89fb---vidanisasenafinamedutasel.pdfIn PDF document text
    • http://omgmediatank.com/userfiles/files/1509241751.pdfIn PDF document text
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/34951601018.pdfIn PDF document text
    • https://shih-tzu.ro/files/file/4606273144.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/160ab7938a5ecb---baxusinubuma.pdfIn PDF document text
    • https://essaidafm.com/uploads/FCK_files/file/41234580106.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/lmrmpu1jlbht5jhi49e3apfhh0/33832829906.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c6e032c6e47---13559744725.pdfIn PDF document text
    • http://chromowane.com/userfiles/file/petenevesoladituzexosifiw.pdfIn PDF document text
    • http://heaig.org/editor/ckfinder/userfiles/files/gamigol.pdfIn PDF document text
    • https://wpsqld.com.au/wp-content/plugins/super-forms/uploads/php/files/55fe4b6935ddc58a8548cc8639cebcff/72517334971.pdfIn PDF document text
    • http://sro52.ru/uploads/files/34760214785.pdfIn PDF document text
    • https://telewebmarketing.com/FCKeditor/file/saxapirosidoj.pdfIn PDF document text
    • http://www.christianhouseshare.com.au/ckfinder/userfiles/files/20035545416.pdfIn PDF document text
    • https://www.sibirprokat.ru/ckfinder/userfiles/files/fopizepofipilikebe.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/160c948c850595---zevibilewanofiwekife.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/16081209dca420---19538598430.pdfIn PDF document text
    • http://p-itos.net/admin/userfile/image/file/24787367297.pdfIn PDF document text
    • http://aeronautike.com/userfiles/file/koxatude.pdfIn PDF document text
    • http://asesorgubernamental.com/images/file/tinateroduxoludowod.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/49823548094.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_off0000d3d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3D8 19736 bytes
SHA-256: db214c812809baf5504b1b7f4638ae1e531d68f6b63661ab3b7d13b05f98ff81
font_01_sfnt_off0001083d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1083D 10460 bytes
SHA-256: 3e21cff874725d3b170faee69df164e85137256643785e21a8950df14c4caaa0
font_02_sfnt_off00011fa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FA9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1