Malicious PDF — malware analysis report

Static analysis result for SHA-256 794f0497bf909a5b…

MALICIOUS

PDF

71.6 KB Created: 2021-09-16 19:20:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f7a6108f008c4ed4e0f34c7596f66b80 SHA-1: 37278aaf9652c10734bbccb1de905e963dfbc714 SHA-256: 794f0497bf909a5b4cf0ad0f84ca13fe025f59cd24954b4c57612e220647627c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest a phishing or malware distribution scheme. The ML classifier and ClamAV detection further confirm its malicious nature, likely serving as a lure for initial access via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://totoquynhhuong.com/upload/files/77955234986.pdf In PDF document text
    • https://fotokeramika.bg/userfiles/file/83314083298.pdfIn PDF document text
    • http://tieulongcopro.com/luutru/files/pepel.pdfIn PDF document text
    • http://computerdoki.hu/user/file/jifososurinakegisozuta.pdfIn PDF document text
    • https://toppelletmachine.com/d/files/nizoxepim.pdfIn PDF document text
    • https://saleskerala.com/ckfinder/userfiles/files/kexikuzezutujeniboje.pdfIn PDF document text
    • http://brenderup.ro/mm/file/5748522949.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/16824464306.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/78023e4f8f7e1679c586643b7c307f3e/69921633592.pdfIn PDF document text
    • http://sparan-art.ru/ckfinder/userfiles/files/44854521994.pdfIn PDF document text
    • http://rafaelokazakov.com/file/gekimodawebumoda.pdfIn PDF document text
    • https://alkirbilaw.com/userfiles/files/88736047842.pdfIn PDF document text
    • http://smsgurugram.com/miet/assets/files/40080080192.pdfIn PDF document text
    • http://vinaktv.com/storage/ckfinder/files/42062454030.pdfIn PDF document text
    • http://hoangduy.vn/vn/files/wikatorowixapatorev.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/f51d00242470b0ebac2347ab6e66c3e8/geguxodivunu.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/ksh4i6883cucr3vghu8g4usagv/65476405122.pdfIn PDF document text
    • https://mamap.in/ci/userfiles/files/49219191156.pdfIn PDF document text
    • https://juraganmonyet.com/contents/files/35242393013.pdfIn PDF document text
    • http://runwellconsulting.com/file/file/79877052788.pdfIn PDF document text
    • http://xn--80adpfaaeictf0c6c7i.xn--p1ai/public/file/13451025711.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/0204qkva7ht9skvjlvciu9sokc/79946695457.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613f3e22d9971---54980005817.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210914131210.pdfIn PDF document text
    • http://alemotta.com/resources/original/file/votedozelujaxetetamu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=julius+caesar+modern+english+pdfPDF 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_off0000b797.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB797 11060 bytes
SHA-256: 6d401616687115e92b112e306473d1c54a473e60e552017a9ffff405c50e87d2
font_01_sfnt_off0000d0e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e8f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8F3 15608 bytes
SHA-256: eb991dcf7c1592385ae35a6c1192701b4c47de30ca45be9406f1ad14785e95e2