Malicious PDF — malware analysis report

Static analysis result for SHA-256 669ae09d90e0425c…

MALICIOUS

PDF

69.5 KB Created: 2021-10-03 04:55:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 4cf2e67118ab9c503cd8ef74053bd8e9 SHA-1: 621407d0ce15e1cb87e5323764208882510892b2 SHA-256: 669ae09d90e0425cf00877bad3490f0918515c2e1c066eb6153b40a3d2977e67
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to manipulate search results or host malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and link farm heuristics point towards an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://zubrcup.by/files/files/20659437098.pdf In PDF document text
    • http://opgzvh.hr/upload/file/3634088905.pdfIn PDF document text
    • http://brno-skoleniridicu.cz/ckfinder/userfiles/files/77658328932.pdfIn PDF document text
    • https://vadihosting.com/calisma2/files/uploads/sazofimowa.pdfIn PDF document text
    • http://phutunggiahungoto.com/uploads/files/52914763979.pdfIn PDF document text
    • https://termofriz.rs/files/gogogosi.pdfIn PDF document text
    • http://giovanniseneca.eu/userfiles/files/36528330396.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/9pmmqfu6sgas80r4e0pn2s566p/sowisupo.pdfIn PDF document text
    • http://e-district.org/userfiles/file/lutabe.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161562740f0eb2---sokojamuboreji.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/zodixijexigikobudul.pdfIn PDF document text
    • https://olivermilk.vn/tctt/sites/aaa/file/99250548402.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/161441b9119c44---melanariwejalot.pdfIn PDF document text
    • https://amzentransportationindustries.com/admin/imagetemp1/file/dazezokujobefun.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613a085334aa2---13840882826.pdfIn PDF document text
    • https://vanchuyenduongsat.vn/upload/files/82595483755.pdfIn PDF document text
    • http://vervesimuhub.com/userfiles/file/90186809151.pdfIn PDF document text
    • https://sieseam.org/userfiles/files/rexekinodaminizukezegerul.pdfIn PDF document text
    • https://faguaflowers.com/images/admin/file/xoxagifakorolup.pdfIn PDF document text
    • http://geoman.cz/data/file/96361396516.pdfIn PDF document text
    • http://jjw-led.com/userfiles/file/75214190855.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/16150aac3b03c9---moziduxow.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/11sgkoc3v3en6df2p7ltvodu67/lukixavijede.pdfIn PDF document text
    • http://3gr-group.com/ci/userfiles/files/zeronixifibovitiberafijaw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=payable+meaning+in+accountingPDF 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_off0000b09b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB09B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c8b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8B2 10660 bytes
SHA-256: 19e242ed0b8b13392d62a9d4c68f509cc6c437282718f0b99b6e71fd12414f38
font_02_sfnt_off0000e11e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE11E 15492 bytes
SHA-256: 5b181934232f336506a40ed9baa4d9b68190c74a857be84d4fa901532c2f093d