Malicious PDF — malware analysis report

Static analysis result for SHA-256 843ae11bb481082e…

MALICIOUS

PDF

76.8 KB Created: 2021-09-15 13:47:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 0a49e7d3783023477dee649e5cee8599 SHA-1: f350be93ad4d22c73fd7054540c9ce1fe618bb83 SHA-256: 843ae11bb481082e70622ff6b392408832f558fa46e5a6e9a47765216ecfa2cd
156 Risk Score

Malware Insights

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

The PDF file contains numerous external URIs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://crysiq.ru/uplcv?utm_term=counter+strike+source+android+apk PDF link annotation
    • http://graviroz.hu/ckfinder/userfiles/files/53503727983.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/0e1a7b08dde1eb9ce39d0406adb9b552/30824822857.pdfIn PDF document text
    • http://xn--54-dlcdkamdj4btild5b.xn--p1ai/ckfinder/userfiles/files/88831306994.pdfIn PDF document text
    • http://topliving.sk/userfiles/file/konowaxoxotu.pdfIn PDF document text
    • http://suncitygroup.ir/basefile/suncitygroupir/files/77294896068.pdfIn PDF document text
    • http://nicenpos.com/userData/board/file/11843438468.pdfIn PDF document text
    • http://bbu.vn/Images_upload/files/53039253903.pdfIn PDF document text
    • http://ueros.fr/admin/ckfinder/userfiles/files/72643478956.pdfIn PDF document text
    • http://dobrasekacka.cz/userfiles/file/39774168528.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613f801909e91---jajapajufe.pdfIn PDF document text
    • https://novamakine.com/upload/ckfinder/files/vujuzuv.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9f8095137---75679139951.pdfIn PDF document text
    • http://conganbacgiang.vn/app/webroot/uploads/files/81201618300.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/zotozor.pdfIn PDF document text
    • https://geloracinta.com/contents/files/29673985407.pdfIn PDF document text
    • http://newo.ru/files/files/59248561503.pdfIn PDF document text
    • http://jnnycc.org/userfiles/file/januvok.pdfIn PDF document text
    • https://leosservices.com/userfiles/file/tizafizunof.pdfIn PDF document text
    • http://zentrumok.com/userfile/files/rexozegojuwavekaparo.pdfIn PDF document text
    • http://sakurahoaanhdao.com/webroot/img/files/57857366187.pdfIn PDF document text
    • https://gtijsr.com/userfiles/file/72543375397.pdfIn PDF document text
    • http://www.aamuhsv-madisonalumni.org/files/files/fikeguvabexukave.pdfIn PDF document text
    • http://ourpreferred.com/userfiles/files/12733666839.pdfIn PDF document text
    • http://cioccolatogallucci.it/userfiles/file/loxiloxer.pdfIn PDF document text
    • http://s250801404.onlinehome.fr/img/uploaded/file/viwukuloruviraga.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_off0000c5e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ddfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDFC 10684 bytes
SHA-256: 4aa48b707a574449b85a4c3289b828a69b4ff4aa325166a7e54b83add4d25d35
font_02_sfnt_off0000f6ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6AE 17940 bytes
SHA-256: 9b4a310f939413f80c1a1b02b06d669035f91a0c38aad0e81ee98d206fcfc180