Malicious PDF — malware analysis report

Static analysis result for SHA-256 f23e3f00d99fdd7b…

MALICIOUS

PDF

111.8 KB Created: 2021-09-19 07:45:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ed144fefe03f1dd6ced124b98dced893 SHA-1: 601a906535df4fd690a91145503148220c6c39c7 SHA-256: f23e3f00d99fdd7bc6bf54912b0140723171817352f5a02452f68b8afafd91b0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links pointing to compromised WordPress sites and disposable hosting, characteristic of a link farm used for phishing or SEO abuse. The document body is heavily obfuscated, preventing a clear understanding of its direct user-facing content, but the overall structure and URL analysis strongly suggest a malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136111008270---92654731320.pdf In PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135067dbc0a3---vunimuwenopoxabigosonifow.pdfIn PDF document text
    • http://studiofantino.it/userfiles/files/91362220253.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/16131f8632d483---datubigi.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021091119551882.pdfIn PDF document text
    • http://omni-links.com/images/blog/file/xinekebilanimekizelezed.pdfIn PDF document text
    • http://irodaszer.lukinserv.hu/file/73181058026.pdfIn PDF document text
    • https://marikakozmetika.hu/editor_up/77457193684.pdfIn PDF document text
    • https://ntpuvoice.com/ckfinder/userfiles/files/wimovaxorejewage.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c750328eac---desatitesizabewojijozifo.pdfIn PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/161399401dcbc9---ditimezefozasiseripu.pdfIn PDF document text
    • https://thietkewebseo.com/webroot/img/files/fasoxixedabaxezamusezol.pdfIn PDF document text
    • http://kozelsk-adm.ru/files/uploads/files/kezesenapakaropuza.pdfIn PDF document text
    • http://abpjseah.news-read.com/upload/files/tixuxez.pdfIn PDF document text
    • http://grandioso.asia/editor_upload_image/file/vomebuwedura.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613a8331d5453---65152614296.pdfIn PDF document text
    • http://cbcom.eu/ressource/site-image/files/jexupifa.pdfIn PDF document text
    • http://upasamed.org/Content/uploads/files/fijiduvewodukiz.pdfIn PDF document text
    • http://budohurtsa.pl/userfiles/file/tanevuvegeregomu.pdfIn PDF document text
    • http://savaksangida.com/resimler/files/lagitizewajaxularep.pdfIn PDF document text
    • https://hfbee.tw/upload/ckfinder_temp/files/20210910175306.pdfIn PDF document text
    • http://yyfxsw.com/upload/files/xifexuvilajarepa.pdfIn PDF document text
    • https://autoandtruckrepair.net/nbloom/fckuploads/file/vojumanoxiwamupafiwitubu.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/af73c3d15690d71460c28e9358dbcf57/59435786238.pdfIn PDF document text
    • https://fishuntpesca.it/file/konejome.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=sword+art+online+alicization+war+of+underworld+part+2+ep7PDF 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_off0001438b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1438B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00015ba2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15BA2 10936 bytes
SHA-256: cfb38a33e16b67af5e51543efc37653ff03d0f190877a682f4bd6c362630a5ee
font_02_sfnt_off00017542.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17542 23288 bytes
SHA-256: 3ac06c311550ae7ff9945e826543b89f0c0f764a4396c118b98973fa6c82d2a4