Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6f1645274ad6f63…

MALICIOUS

PDF

79.6 KB Created: 2021-09-19 23:35:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c5dbaf66d63e234a9df26883249bea72 SHA-1: 7179ed79e632fd55ca543730cb44412a5dfc1e19 SHA-256: a6f1645274ad6f63c9b4a0c7491c4ff438cddbe5fabde902ddd57baefa3702f4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised websites 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 malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://infrive.ru/uplcv?utm_term=9th+std+biology+textbook PDF link annotation
    • http://leoclubmarsala.it/userfiles/files/65528377088.pdfIn PDF document text
    • https://www.totalblissbeauty.com.au/application/third_party/ckfinder/userfiles/files/lofaligilupo.pdfIn PDF document text
    • http://ibconsulting.it/userfiles/files/16686933475.pdfIn PDF document text
    • https://highlander-inn.com/assets/userfiles/files/73798431372.pdfIn PDF document text
    • http://yidaig.com/uploadfile/file/20210916090837.pdfIn PDF document text
    • http://studiobaliva.eu/userfiles/files/74856090256.pdfIn PDF document text
    • http://alde-pace.org/ckfinder/userfiles/files/tevonaliwesule.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/161384c71b6afa---23720368043.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/16134a660dd62d---22841032391.pdfIn PDF document text
    • http://fukaofoods.tw/uploads/files/202109120358257388.pdfIn PDF document text
    • https://buddhaart.in/userfiles/file/30338065359.pdfIn PDF document text
    • http://abovomedia.hu/_user/file/7244188901.pdfIn PDF document text
    • https://hitourkorea.com/FileData/ckfinder/files/20210914_1B810013C77B7452.pdfIn PDF document text
    • https://sahyadrisevasanstha.in/userfiles/file/segolorunenirafidilozeruz.pdfIn PDF document text
    • https://macintosh-szerviz-javitas.nuttydog.hu/ckfinder/userfiles/files/sasasolufir.pdfIn PDF document text
    • http://klick-tipp.at/ckfinder/userfiles/publics/files/silakibap.pdfIn PDF document text
    • http://3e-recycling.ru/app/webroot/filesfiles/87622760794.pdfIn PDF document text
    • http://www.mab-solutions.fr/upload/file/27949547458.pdfIn PDF document text
    • http://vikingpaint.com/user_file/file/zakoxenalos.pdfIn PDF document text
    • http://mansiya.com/uploadfile/files/92467469244.pdfIn PDF document text
    • http://hibertek.com/image/files/20210909_004959.pdfIn PDF document text
    • http://suliaok.com/v15/Upload/file/202191975259429.pdfIn PDF document text
    • http://nensi.si/upload/file/xidirovisoromiwokoban.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b2a9c65c33---mawanuvotarupow.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_off0000d216.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD216 10680 bytes
SHA-256: af8d7f80da1a6433d218878fc69c28a6f8e2572e10fdca364b8e75478f909da8
font_01_sfnt_off0000ea80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA80 17988 bytes
SHA-256: 92fbd49232b068c9a6f25bcacdcf717ec57561d866742bf06c2ac96bfa1da6ce
font_02_sfnt_off00011967.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11967 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1