Malicious PDF — malware analysis report

Static analysis result for SHA-256 4878d76f45bbe8a2…

MALICIOUS

PDF

69.8 KB Created: 2021-09-27 21:47:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 6f6233df11afe1c32a245e23f8f4b289 SHA-1: 364c2b2d62f89746672a98e16e65d2273aed996c SHA-256: 4878d76f45bbe8a24b18a8171039464555edc028e562c21e90b04c47c9015cd6
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with multiple URLs pointing to potentially compromised websites or disposable hosting. The presence of external URIs and link farm characteristics suggests an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://qhzs88.com/admin/fckeditor_upfiles/file/2021090710155780554.pdf In PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133f0b6c0fe1---zarototemekuwomevibisib.pdfIn PDF document text
    • http://przyrodnik-kujawy.eu/userfiles/file/7295624965.pdfIn PDF document text
    • http://pro-elec.ru/ckfinder/userfiles/files/babituxasetazodeferiki.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/ano20h1vb4lkt79ffcqdfdfgn0/nuwufaw.pdfIn PDF document text
    • http://mopi.eu/ckfinder/userfiles/files/21056535868.pdfIn PDF document text
    • http://xn--9w3b270a7kf.kr/data/editor/file/tawufunofuwovumivorizud.pdfIn PDF document text
    • http://bukharaalpharetta.com/sites/default/files/file/49448544399.pdfIn PDF document text
    • http://velkoobchod-man.eu/ckfinder/userfiles/files/51282577116.pdfIn PDF document text
    • https://socialacademy.gr/wp-content/plugins/super-forms/uploads/php/files/5d9d68a9c9a7685f2ca8028251629218/777285897.pdfIn PDF document text
    • http://aweibel.com/Photo/file/fudofivifanizuw.pdfIn PDF document text
    • https://klubkanine.com/home/klub/public_html/ckfinder/userfiles/files/nogoninuzanut.pdfIn PDF document text
    • http://progettarecasa.com/userfiles/files/55816798606.pdfIn PDF document text
    • https://damiel.eu/userfiles/file/gosegefogumupuw.pdfIn PDF document text
    • http://sevimticaret.net/userfiles/file/62054618382.pdfIn PDF document text
    • http://dogalakustik.com/depo/sayfaresim/file/kexukabupitobotegon.pdfIn PDF document text
    • https://sindicav.com.br/ckeditor/ckfinder/userfiles/files/lomako.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613be02b6274e---67105144035.pdfIn PDF document text
    • http://phantasos.org/userfiles/file/33086865283.pdfIn PDF document text
    • https://mchs.kz/userfiles/File/gibapatines.pdfIn PDF document text
    • https://svetplus.com/userfiles/files/86707155799.pdfIn PDF document text
    • http://szyoujin.com/UploadFile/file/20210905220140120.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=followers+gallery+apkPDF 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_off0000af51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF51 17080 bytes
SHA-256: 58726baae974fbef54cea6c7fb6be4d17f406f46650c52a1a3a308230bf42d88
font_01_sfnt_off0000da4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA4F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f266.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF266 10404 bytes
SHA-256: 3d2ec9b6d4a140ddce65c0cd2e7c10631c0b8dcdecb899c9105f1b6aac688bf7