Malicious PDF — malware analysis report

Static analysis result for SHA-256 c819b638c1ccc835…

MALICIOUS

PDF

83.8 KB Created: 2021-09-14 01:06:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 91a913ae44392d20f68c74f66ef87f8d SHA-1: a92e1dcdb52a3f9ade138b6b8250e9d60bdf5101 SHA-256: c819b638c1ccc835f84e51bd135c3cc0da03e5138f5e5ac7b9291b0e79bc5c17
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with multiple URLs pointing to various domains, many of which are hosted on compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the structure and URL patterns suggest an attempt to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://astefin.ro/ckfinder/userfiles/files/25948865197.pdf In PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/161303e8858a91---denixezuwojibazes.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ccf985ba3c---61285456419.pdfIn PDF document text
    • http://portaldeaquidauana.com.br/ckfinder/userfiles/files/13707624800.pdfIn PDF document text
    • http://wimborst-ceramics.nl/ckeditor/ckfinder/userfiles/files/24060448725.pdfIn PDF document text
    • https://nasco-ye.com/uploads/file/jalogemikefev.pdfIn PDF document text
    • http://josepholszowka.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/68229072413.pdfIn PDF document text
    • https://kultmotor.hu/images/files/24656809906.pdfIn PDF document text
    • http://the100voicesofgospel.ch/fichiers/newsletter/file/nadimutiweporumajod.pdfIn PDF document text
    • https://turismo-galicia.es/ckfinder/userfiles/files/sitot.pdfIn PDF document text
    • http://hybsch.it/upload/file/7334339444.pdfIn PDF document text
    • http://www.rannatennis.ee/data/upfiles/files/15375222426.pdfIn PDF document text
    • https://fotografski-studio.kost.si/userfiles/file/80460847657.pdfIn PDF document text
    • http://vicc.huh.hu/UserFiles/File/38167286824.pdfIn PDF document text
    • https://derya.afmiletisimajansi.info/resimler/files/3666118430.pdfIn PDF document text
    • http://webminmax.com/userfiles/file/65717669322.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136e514e9d0b---65922396260.pdfIn PDF document text
    • http://biblioteka-belzec.pl/upload/files/8391790277.pdfIn PDF document text
    • https://vsevolozhsk.mebel18.com/uploads/files/vogodoxalet.pdfIn PDF document text
    • http://professional-tuner.at/uploaded/file/zewafan.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/0db542d049807353edbdce2f896c83cb/38273366123.pdfIn PDF document text
    • http://d2dgroup.net/upload/files/6612031077.pdfIn PDF document text
    • https://ijmscr.com/ckfinder/userfiles/files/30469096147.pdfIn PDF document text
    • http://dlevitin.ru/fck_editor_files/files/rutovosakeduwetakore.pdfIn PDF document text
    • http://giaodantanthaison.com/Images_upload/files/govulumuxopubafes.pdfIn PDF document text
    • https://ceccardolj.ro/userfiles/file/tuvuvinu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=master+brawl+apkPDF 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_off0000d9fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9FE 10240 bytes
SHA-256: 57e1ca44c771e94e12007b5fe9a2e0291ffb1e31befbe5367d7b01f77288589b
font_01_sfnt_off0000f104.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF104 21480 bytes
SHA-256: c488bc272489e137dccd22cd7b79690b8a393e376330416c8c461f61c92e8c03
font_02_sfnt_off00012962.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12962 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1