Malicious PDF — malware analysis report

Static analysis result for SHA-256 8435a1c09bc16255…

MALICIOUS

PDF

87.2 KB Created: 2021-07-08 08:44:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 4eb2c30915bd49ec8af4eafb34282fe7 SHA-1: 5aeb96de101a9f3194fa83a52b41ce821ba062eb SHA-256: 8435a1c09bc16255c92d36bf708fcf9bc18c58abf0d6bc337e7a918b07e5a0f1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a malicious document, potentially leveraging embedded JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://ketchas.ru/uplcv?utm_term=the+glass+house+philip+johnson+pdf PDF link annotation
    • http://zuche0551.com/upload/file/66294688887.pdfIn PDF document text
    • http://abacusnancy.com/userfiles/file/zukojijezevetejib.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/16080f5a27b414---zuverawofojaxat.pdfIn PDF document text
    • http://mail-ex.net/userfiles/file/56415767925.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160745a153bb1f---gureravajilames.pdfIn PDF document text
    • https://bojovicsirogojno.com//files/5424226640.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/94026605569.pdfIn PDF document text
    • https://tl-systems.hu/files/files/89435714034.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/14070622785.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1609842b9d636a---85420096030.pdfIn PDF document text
    • http://cariboohose.com/userfiles/file/73217708462.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073015439300---metof.pdfIn PDF document text
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/e625521e355879e57d1c5bf81690c45f/12264809707.pdfIn PDF document text
    • https://bladmedyczny24.pl/wp-content/plugins/super-forms/uploads/php/files/c2b5c012697392fd3aafa2881d0577c5/66409504364.pdfIn PDF document text
    • http://apexhealthnutrition.com/newerac2c/userfiles/file/68716021525.pdfIn PDF document text
    • http://akgikorea.com/file_upload/fck_upfile/file/taridiripak.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a56109d4d04---69574516783.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/9c4d5ee1239954187e2890eac52e6947/zewafujetevif.pdfIn PDF document text
    • http://timebymtm.com/upload/files/kipolekawovuwuzomupe.pdfIn PDF document text
    • http://grawerlik.pl/userfiles/file/zanavamojiruferukobuzafe.pdfIn PDF document text
    • https://magyar-logyogyasz.hu/fileok/file/tezotesijadubedokonasumif.pdfIn PDF document text
    • https://kamarkosong.com/contents//files/18391805860.pdfIn PDF document text
    • https://stonebuild.bg/f/uploads/files/84280328521.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/b6c38278a03a5a381918d66486c68ebf/45905480865.pdfIn PDF document text
    • http://farmaciacogliate.it/userfiles/files/nurolemanuvefopewalowot.pdfIn PDF document text
    • https://digidatadecolombia.com/wp-content/plugins/super-forms/uploads/php/files/a44a3d68973e2ba1cf74e497e1fd64d2/3470191460.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_off0000f12e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF12E 17012 bytes
SHA-256: 16384a5540600a34e8dcf3fbb117667d45e3299f0c12deff5342ae2384b4c71d
font_01_sfnt_off00011d67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D67 10772 bytes
SHA-256: dfd5f8fadf4b496898a6aef99d7b166e29b125b5d8dc158890364a3a9b80cecb
font_02_sfnt_off000135dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1