Malicious PDF — malware analysis report

Static analysis result for SHA-256 6496150658776d2a…

MALICIOUS

PDF

69.4 KB Created: 2021-09-26 17:46:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ccdb17c1c8d588b5fdfd1088eee6c033 SHA-1: dd2b8e5962faca37e9461b3c9785b16f14e8c46b SHA-256: 6496150658776d2ab9869623ffe501eb90743745552a876c22586e188fc0f0af
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external URIs and link farm patterns, indicating an attempt to redirect users to potentially malicious websites. The ML classifier and ClamAV detection strongly suggest malicious intent, with the sample being identified as a phishing trojan. The presence of compromised CMS upload links further supports the malicious nature of the document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 https://crewmak.ru/uplcv?utm_term=the+average+rate+of+change+of+the+function PDF link annotation
    • http://kuryakyn.ru/userfiles/file/loxuwonaputuzogoxubelazit.pdfIn PDF document text
    • http://luyenthidhcanhsat.com/Images_upload/files/vofiguraz.pdfIn PDF document text
    • http://sigmabhp.pl/userfiles/file/8728918403.pdfIn PDF document text
    • https://kemxoi.vn/app/webroot/files/images/pages/files/kopojeviwiwofob.pdfIn PDF document text
    • http://ls12368.com/userfiles/file/delemageronedowozewedaj.pdfIn PDF document text
    • https://www.comperat-89.fr/ckfinder/userfiles/files/wazalom.pdfIn PDF document text
    • https://www.idd.no/ckfinder/userfiles/files/50298097342.pdfIn PDF document text
    • http://hengtaixin.com/HangShun/ckfinder/userfiles/files/kevatipuso.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/ha1dob58elq0tm5vfhtnumai4s/zemadigegevalojagim.pdfIn PDF document text
    • http://cmtdental.com/upload/ckimg/files/52116005992.pdfIn PDF document text
    • http://interstroy96.ru/uploads/files/76846811993.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134dc0d20aef---88023951508.pdfIn PDF document text
    • https://dom4m.com/userfiles/files/81837529665.pdfIn PDF document text
    • https://digireg.com/upload/tikenile.pdfIn PDF document text
    • http://ff-engineering.com/userfiles/files/tupobutux.pdfIn PDF document text
    • http://sziazsauto.com/uploads/files/bakipa.pdfIn PDF document text
    • https://classykitchen.pl/web/uploads/files/retofojivowidaparezubaro.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/161356e889608d---58798244986.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161302ffc5a45e---21964163205.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612f41e044d3c---niniribisol.pdfIn PDF document text
    • 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_off0000ace9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xACE9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c4fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4FB 16676 bytes
SHA-256: 2b89cb8728c658bedb8b408237352507e6f45de81b4ceab17e22379df6b5c903
font_02_sfnt_off0000efff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFFF 10532 bytes
SHA-256: 88cc474a9a9a0e3b90bb2385a515f367976e76e146be7e3d93e0dd2a725af592