Malicious PDF — malware analysis report

Static analysis result for SHA-256 34f9dd69823a3722…

MALICIOUS

PDF

93.5 KB Created: 2021-09-18 21:16:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: fad2e36c337a2a3d95eda1927419309f SHA-1: b77736b6efd1289bd7805cdaafe0ea14570ca598 SHA-256: 34f9dd69823a37224e70ad956f5291489589f92a6cc596e7b2ca64e0b24541d7
156 Risk Score

Malware Insights

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

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically identified as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to various websites, some of which are hosted on compromised WordPress uploads or disposable domains. This suggests an attempt to lure users to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://at-studio.tw/app/webroot/userfiles/files/20210911_191043.pdf In PDF document text
    • https://valerart.com/ckfinder/userfiles/files/69978287864.pdfIn PDF document text
    • http://sendedianqi.com/upload_fck/file/2021-9-2/20210902110256497931.pdfIn PDF document text
    • https://xeroxexpres.cz/userfiles/file/zepisavoselafekolu.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137d349146de---zukugo.pdfIn PDF document text
    • https://kga-am-adlergestell-ev.de/kga/ckfinder/userfiles/files/4419750619.pdfIn PDF document text
    • https://asiarsolutions.com/userfiles/file/sebasejerubikezoduviziwum.pdfIn PDF document text
    • http://jadeite.ru/images/file/negofofitinanisedipazonum.pdfIn PDF document text
    • http://basumati.com/app/webroot/ckfinder/userfiles/files/vebedomukiziloxet.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/ob4n31q2ulq7986o4vdk5mcb7l/tatafonorofimamefixuz.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613150e358e9f---nokizutidanerebow.pdfIn PDF document text
    • http://www.klccpa.com/userfiles/file/In PDF document text
    • http://iact2001.com/userData/board/file/39473166212.pdfIn PDF document text
    • http://bretagne.annuaire-regional.com/ckfinder/userfiles/files/wumosubotatukesoti.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613d79831ff71---vapitunomogezov.pdfIn PDF document text
    • http://hillsclinic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/jowiw.pdfIn PDF document text
    • http://naim.naparts.com/images/fck/file/litalase.pdfIn PDF document text
    • http://fohow77.ru/upload/file/35602644465.pdfIn PDF document text
    • http://kunjipsc.com/uploads/files/digadojubakefofobodapu.pdfIn PDF document text
    • https://royal-art.pl/uploads/userfiles/files/77111495929.pdfIn PDF document text
    • https://vinatech.com/userfiles/file/32161087914.pdfIn PDF document text
    • https://bepcongnghiepphuchung.vn/userfiles/file/ruwerafanoxaxidesenuv.pdfIn PDF document text
    • http://zuche0551.com/upload/file/33739913332.pdfIn PDF document text
    • http://www.taimaobi.com/admin/ckfinder/userfiles/files/12745101292.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=android+apps+websitePDF 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_off000109b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000121c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121C6 17812 bytes
SHA-256: e4f7c3e42ed7ae61e3fed9ff4819ceb69d41e794c743afae242590f6b00b7656
font_02_sfnt_off00015054.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15054 10544 bytes
SHA-256: 8f3b82896cc4ee9dd64f09042983f261604418fbbdf5db12575b19543be19ac6