Malicious PDF — malware analysis report

Static analysis result for SHA-256 8de50bf29726ef96…

MALICIOUS

PDF

88.6 KB Created: 2021-09-22 13:22:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a33307cb9911510eeb63b04fe52f80d1 SHA-1: dceb1ed72d7d02b15756564cf206660ce38e8d3b SHA-256: 8de50bf29726ef963f2666d59a54f2e535a0700fd3be039dfd983d9498346dac
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs and link farms, suggesting it's designed to redirect users to potentially harmful websites. The presence of compromised CMS upload links further supports a malicious distribution or phishing scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://krisoc.ru/uplcv?utm_term=free+classic+movies+to+watch
    • https://thuaphatlaihanoi.net/uploads/files/xumojokijo.pdf
    • http://kocavietnam.com/upload/files/mizopumiwonej.pdf
    • http://adec-interiors.net/Uploads/file/37000511139.pdf
    • https://karapinarinsaat.net/userfiles/upload/file/digevek.pdf
    • http://iviltra.lt/images/files/wofijurudaloz.pdf
    • http://e-kva.ru/admin/ckfinder/userfiles/files/25039950848.pdf
    • https://myarchitect.es/ckfinder/userfiles/files/pupekuput.pdf
    • https://mimpidia.com/contents/files/nimezetanefigido.pdf
    • http://escalierdurire.fr/ckfinder/userfiles/files/90439797140.pdf
    • http://xn--b1agjlwjc3g.xn--p1ai/ckfinder/userfiles/files/41823725451.pdf
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/16148679a63e7b---6698380763.pdf
    • https://chief-moving.com/editor_upload/file/numadekoxazaverarokewabiw.pdf
    • http://themetamorphoseprogram.com/userfiles/file/dagoxoseva.pdf
    • https://nonbodepsg.com/uploads/files/22787262966.pdf
    • http://pitchdecor-construction.com/user_img/files/xurujekijodolut.pdf
    • http://geojeoceanhotel.com/userfiles/file/20210918170259.pdf
    • https://dehayemek.net/upload/ckfinder/files/kugubowa.pdf
    • http://pnmanagementsolutions.in/uploads/16840570855.pdf
    • https://goodluckfishing.com/ckfinder/userfiles/files/78637165588.pdf
    • https://llbyggodesign.se/UserFiles/files/wokuwomabot.pdf
    • http://www.southforconstruction.com/frontend/web/ckfinder/userfiles/files/sesoputoke.pdf
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/r6v4n5r1a84nq6mlljb6u2lt36/19814906937.pdf
    • http://kayapalinakliyat.com/file/vabomapajomotagepurutu.pdf
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613e67762dce5---40054182045.pdf
    • https://minhkygroup.com/luutru/files/89866431292.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f78e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF78E 16792 bytes
font_01_sfnt_off00010fa0.bin
53b994c48eabc956d7d5cf94308fdb53e90b3acc9e7e55b50926653722718ab8
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FA0 17596 bytes
font_02_sfnt_off00013ce6.bin
0b5ae06ea47ecdba5836301f1f01d2e2aa854c635ab2be548b248a02bfa44f8b
pdf-font-stream PDF embedded font (sfnt) at offset 0x13CE6 10520 bytes