Malicious PDF — malware analysis report

Static analysis result for SHA-256 0961a8daca2813a3…

MALICIOUS

PDF

83.6 KB Created: 2021-09-17 04:59:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 63ef374f8a5657022011d16e2c84f1e4 SHA-1: 38a8440228a4a411d9b9b1fe9927725836f31d2a SHA-256: 0961a8daca2813a366d0d5904bb2781eaaa1fef1c7180b5cb457d8223d4e977c
174 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and a high-risk heuristic firing for a link to an algorithmically-generated URL, indicating an attempt to redirect the user to malicious content. The ML classifier and ClamAV detection strongly support its malicious nature. The sample's purpose appears to be distributing further malware via a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://aiaato.com/FileData/ckfinder/files/20210914_E547AFD4BB14EC09.pdf In PDF document text
    • http://slavutich-media.ru/userfiles/file/zajemunoximaxibura.pdfIn PDF document text
    • https://eletvital.hu/uploads/files/12963486736.pdfIn PDF document text
    • https://himalayanthailand.com/image/upload/File/45087225961.pdfIn PDF document text
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/95253514267.pdfIn PDF document text
    • http://thietkewebsite.btccorp.vn/uploads/files/73430189135.pdfIn PDF document text
    • https://thisissati.com/userfiles/files/82546157388.pdfIn PDF document text
    • http://sanchariglobal.com/userfiles/file/51229191326.pdfIn PDF document text
    • http://sinching.com/uploadpic/files/202109091908212196.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/16131549607085---41627354093.pdfIn PDF document text
    • http://fujiya-burbank.com/uploads/files/jugajibuger.pdfIn PDF document text
    • http://downtowncincyhotels.com/core_degree/admin/images/cms_imagesfiles/fajilabudin.pdfIn PDF document text
    • http://ambulatorioveterinariosanfrancesco.com/userfiles/files/xedaxazarudezuguvi.pdfIn PDF document text
    • http://karthikeyanjayaram.com/userfiles/file/debolanopila.pdfIn PDF document text
    • https://vietnaminsight.biz/ckfinder/userfiles/files/71827206849.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-9-2/20210902093128496131.pdfIn PDF document text
    • http://logenamerica.com/userfiles/file/pomuxemidad.pdfIn PDF document text
    • http://hourinkan.net/js/upload/files/48546596880.pdfIn PDF document text
    • https://singlespeed-switzerland.ch/userfiles/files/goxirofezugivebitekomanu.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143c9c4bf3d9---53026073119.pdfIn PDF document text
    • http://fongyoskert.hu/userfiles/files/10806961577.pdfIn PDF document text
    • http://nomayaku.com/userfiles/file/73958525556.pdfIn PDF document text
    • http://shangyi-pump.com/uploads/file/092023221715.pdfIn PDF document text
    • http://e-instar.com/userfiles/file/raragiboxojurepa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=video+editor+free+for+pc+downloadPDF 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_off0000e1e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f9fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9FA 18128 bytes
SHA-256: ebb06fac7182b6ff4d17709e42271ba7fc990855b2ad1876348ea6ea59ea5879
font_02_sfnt_off000128a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128A2 10500 bytes
SHA-256: 960f0dd05f2ad59b68d6344533931448a34f4ed27880e7579d6f985bad7b389c