Malicious PDF — malware analysis report

Static analysis result for SHA-256 9dc5b1d876a88a03…

MALICIOUS

PDF

94.9 KB Created: 2021-09-12 08:26:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 3206f33671faf1c5425a66980ae65895 SHA-1: 16efdf74d3b1e5d794332cdca6207b90851d9a15 SHA-256: 9dc5b1d876a88a03b1e6932c5bac0634ca1e728722355f0b7b28cda071aed08a
156 Risk Score

Malware Insights

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

The sample was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, directing users to multiple external URLs, some of which are hosted on compromised CMS upload storage. The presence of numerous PDF link farm heuristics indicates a deliberate attempt to obscure the final destination and potentially distribute malware or phish for credentials.

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 https://realxenon.ru/uploads/files/pamedis.pdf In PDF document text
    • http://eastcoastbiker.de/sites/default/files/file/79821735098.pdfIn PDF document text
    • https://www.informacion-indoorclub.com/boletines/img/file/34968318344.pdfIn PDF document text
    • http://tingchucontrol.com/Uploadfiles/files/loliridegeganimidelexe.pdfIn PDF document text
    • https://0924055971.com/uploads/files/202109031302171895.pdfIn PDF document text
    • https://hometutorsdelhi.com/userfiles/files/piduluwu.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/m03pcuhfr1cf5e8vjfee807372/23830093860.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/16133a92fc64a3---84182146317.pdfIn PDF document text
    • https://ximangcampha.vn/upload/files/mogabidow.pdfIn PDF document text
    • http://kes.org/upload/editor/files/92392989087.pdfIn PDF document text
    • https://alternativi.brtim.com/uploads/wysiwyg/files/xagimozalumegilexu.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161396ecc552d6---10761962812.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16136b9c1b8218---54258826222.pdfIn PDF document text
    • http://co-wemart.com/careeruserfiles/file/jediwozemerufew.pdfIn PDF document text
    • https://theshamrockpublecco.it/file/24249962263.pdfIn PDF document text
    • http://www.rpv-drachten.nl/files/file/kagoruxumor.pdfIn PDF document text
    • http://ofitecnic.es/files.ofitecnic/fck_up/file/34444081515.pdfIn PDF document text
    • https://kochitaxirental.com/ckfinder/userfiles/files/sotejugidinadeze.pdfIn PDF document text
    • http://engroupe.ca/aym_image/files/pegudatudefililomudiki.pdfIn PDF document text
    • http://ruiqingchem.com/upload/files/tepefubovevonefapapilik.pdfIn PDF document text
    • https://plantbiochem.com/ckfinder/userfiles/files/zopukezuses.pdfIn PDF document text
    • https://testagenda1.myagenda.cz/pictures/editor/files/57128444370.pdfIn PDF document text
    • http://jullien38.com/ressource/site-image/files/14527545118.pdfIn PDF document text
    • http://liceoadultos.juniorcollege.cl/userfiles/files/72181885603.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=watch+dragon+ball+super+episode+1PDF 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_off00010b40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B40 18356 bytes
SHA-256: 0d9280754fa13fba7af4da2dd8f33ede5a06fd4a4b7a898489288ff7de61db33
font_01_sfnt_off00013af0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AF0 11080 bytes
SHA-256: 161ac30587a1d3f0c83700e400bb9634a65d43b5785d3b875d6b51a2b6575532
font_02_sfnt_off00015456.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15456 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1