Malicious PDF — malware analysis report

Static analysis result for SHA-256 39909f84c528fb51…

MALICIOUS

PDF

86.8 KB Created: 2021-09-04 07:50:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 39b2a917a172bd566740c0ef9b4ee38c SHA-1: 51a15bc090600b6fc8fce9b6718fb64348ae0436 SHA-256: 39909f84c528fb515d4a71620eff1dd256f5c83067b1e0879e673427dcbdd972
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains a link farm pointing to compromised WordPress upload storage and other disposable hosting sites, likely intended to trick users into downloading further malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a non-clustered link farm on disposable hosting, and the PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristic highlights links to compromised CMS upload storage, suggesting a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 http://futureinfashion.com/ckfinder/userfiles/files/8049186827.pdf In PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160a6c1c28f280---91618959421.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/eb3b145131e4b513f8c2eeb34dcd0fba/12213119848.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/0f3a92d838b1045a093f17242019d27a/54375264835.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/r5t326h1pieb5gatq51sinboa6/soviliboju.pdfIn PDF document text
    • http://sobinco.cz/ckfinder/userfiles/files/30591729585.pdfIn PDF document text
    • http://beamstraffic.ae/amb/userfiles/file/fuvisetog.pdfIn PDF document text
    • http://findmecakes.com/userfiles/files/surixijufevevabuxu.pdfIn PDF document text
    • http://sgyscom.com/upload_fck/file/2021-8-30/20210830032149206408.pdfIn PDF document text
    • http://cowmoo.org/ckfinder/userfiles/files/zokuf.pdfIn PDF document text
    • http://dirabrealtors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160871fda1a097---bipenumibaziloretave.pdfIn PDF document text
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/4d29ba2639526f185460d34ebd1325b9/turovobixaxizuzo.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c07a96a387---78282494740.pdfIn PDF document text
    • http://neuragen.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c4c7c56e030---worukunenanijunumarola.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607adba9a1c40---26204746461.pdfIn PDF document text
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/06d65b798520a909cac306af17b8d999/28986532164.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160927b1fd1195---12756835298.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ee60ed42eee---gunufefiresiwimiwupidan.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b48f6a81b31---wumujelubufitupewamewu.pdfIn PDF document text
    • https://rittenhousesmiles.com/wp-content/plugins/super-forms/uploads/php/files/0fa721062c89950937eaa75f27937d9c/wukenexijajevesewokud.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/0d3dbde4eee1bee8e3fd326c3156e794/920937599.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=best+program+to+change+pdf+to+wordPDF 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_off0000eb05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB05 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001031c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1031C 11068 bytes
SHA-256: 8af6f7369438e2551ea8c1c39fbb8226ae748a732065da75ad3afb5f2a51a3fe
font_02_sfnt_off00011ca2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CA2 18908 bytes
SHA-256: 27ecd190398462505d05999df375e3380d9ab211659372ebf96c4c7a3e3cfe63