Malicious PDF — malware analysis report

Static analysis result for SHA-256 5356d1efb981497c…

MALICIOUS

PDF

76.6 KB Created: 2021-09-05 20:48:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 69e470ab3f7dc95192ac628f0dd9a95f SHA-1: 483acb48d21ed3bc7a2cbd9dc74338c6bc382664 SHA-256: 5356d1efb981497ce80603337f559480d2965b6c0790ac76b5132b001f902faa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload storage locations and other disposable hosting sites. This suggests the PDF is part of a phishing or malware distribution campaign, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • 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.
  • 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://architettomontanino.eu/userfiles/files/semosevuluvabodalej.pdf In PDF document text
    • http://thuephotocopytaihanoi.com/upload/files/vibovuwofigowivovupal.pdfIn PDF document text
    • https://wecareu.net/ckfinder/userfiles/files/dapakuxazif.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/12f5b76d24008e5d66ea2ecf67ba0998/402229178.pdfIn PDF document text
    • http://dental-forum.ru/userfiles/file/zulenurobek.pdfIn PDF document text
    • http://mkconline.com/landmark/ckfinder/userfiles/files/wasiwimoboru.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/e9fdg5is692l3i0co9tkib1k01/29844895502.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160c58b21a4882---46351830015.pdfIn PDF document text
    • https://makeswebsites.com/clients/c/c8/c8c605999f3d8352d7bb792cf3fdb25b/File/38341404337.pdfIn PDF document text
    • https://museos.comarcadelasierradealbarracin.es/ckfinder/userfiles/files/64683848820.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e9519222c0---66731420302.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1610021677fe14---kexuroxifo.pdfIn PDF document text
    • http://tunesistudio.eu/userfiles/files/winotajarudusixetudufit.pdfIn PDF document text
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/mmv066ukg1105m49q2c8e1lm0t/jodupupupe.pdfIn PDF document text
    • https://efnnma.org/files/file/togijivurolivekifotovade.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/0l6g3ka9vll0cvihucqgu2gvsp/vevuvazifegapezoviwefuwet.pdfIn PDF document text
    • http://elijasprojekts.lv/files/file/20523518419.pdfIn PDF document text
    • https://dtcprojects.com.au/wp-content/plugins/super-forms/uploads/php/files/vc1ocff1auquhqbinaj1h5klt5/93311786122.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/i6tiuqruvkvhkdfhkmpa22ssup/zakebipinonud.pdfIn PDF document text
    • http://staging.impactredevelopment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d18cee04c7---35708858097.pdfIn PDF document text
    • http://studiofranzoni.eu/userfiles/files/34210880981.pdfIn PDF document text
    • https://felix-schulze.biz/wp-content/plugins/super-forms/uploads/php/files/789r2r3pie44foir4nlip3g7mr/87267485282.pdfIn PDF document text
    • https://deltarealestate-eg.com/userfiles/file/fajujabegubafepov.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ee38c02ad15---gawoxa.pdfIn PDF document text
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608135a7185b0---wojodusafilogugiguxobog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=multiple+page+pdf+to+word+converterPDF 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_off0000c668.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC668 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000de7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE7F 10872 bytes
SHA-256: 826fb0ef5b8b62c5a734fb53a194c20eae0811b8584430f813e3ad400e82765e
font_02_sfnt_off0000f794.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF794 17476 bytes
SHA-256: 3bbdae1248cd135fc78573ffdb6826255b615d8f6a3bb76a2345aa8b072336be