Malicious PDF — malware analysis report

Static analysis result for SHA-256 237cd8b5adf05e2a…

MALICIOUS

PDF

89.8 KB Created: 2021-09-13 09:59:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ef5f68c3c95f0d6d3ea153a7bd6d4ea5 SHA-1: 12ac581fc8cf1e3714629078b5677190a0a2ea52 SHA-256: 237cd8b5adf05e2a5165a671a118f987763b46496474d9dd5f2278b69c3b612e
156 Risk Score

Malware Insights

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

The file is a PDF identified as malicious by ML classifiers and ClamAV, containing numerous embedded URLs. These URLs point to various domains, many of which appear to be compromised or disposable hosting, suggesting a link farm designed to distribute phishing content or malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically indicates this pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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://allytemp.ru/uplcv?utm_term=cordova+clean+android PDF link annotation
    • http://carlaschroyen.com/content_docs/81876806848.pdfIn PDF document text
    • https://arabadvertise.com/userfiles/files/dagojuzirakuwe.pdfIn PDF document text
    • http://bitite.lv/media/txt/122/file/vujabajibusafofewifezof.pdfIn PDF document text
    • https://x-software.cz/data/file/wutaroretagetegoxod.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/pojubuwavugifolupa.pdfIn PDF document text
    • http://gymostrov.org/gymostrov/userfiles/file/tajowuge.pdfIn PDF document text
    • https://rpdev.org/ckfinder/userfiles/files/94332641050.pdfIn PDF document text
    • http://osteriadelcampanile.com/userfiles/files/51545384047.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/161325bbc4c525---16310787188.pdfIn PDF document text
    • http://karinameal.ru/imgdish/files/jokapul.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16135bb36cfa30---logobodunajufogax.pdfIn PDF document text
    • https://aep-tc.com/cache/fck_files/file/dozirod.pdfIn PDF document text
    • https://patriciobanados.cl/upload/file/In PDF document text
    • http://teusz.pl/UserFiles/file/81770232528.pdfIn PDF document text
    • http://vonschickenfremont.com/uploads/files/tifonijejikej.pdfIn PDF document text
    • https://igescanada.com/ckfinder/userfiles/files/3668511056.pdfIn PDF document text
    • https://myagenda.myagenda.cz/pictures/editor/files/piginuwejarimep.pdfIn PDF document text
    • http://jjsgreatescape.com/uploaded_files/userfiles/files/73439213904.pdfIn PDF document text
    • http://moskvaznaet.ru/upload/files/11505540357.pdfIn PDF document text
    • http://valdhans.cz/userfiles/file/39146308803.pdfIn PDF document text
    • https://camelcarpet.org/d/files/45420525032.pdfIn PDF document text
    • https://coastalstudio.com/images/main/file/38522432833.pdfIn PDF document text
    • http://ekotop.eu/userfiles/file/17801206676.pdfIn PDF document text
    • http://dongsimkindergarten.com/upload/files/burewuxedibixin.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/161371ba204e75---fobazikejevo.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_off0000f766.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF766 19520 bytes
SHA-256: 34db9aa2fd613ecd327b13d5706f7fa28ed06621db0f4224dcd09c9d1a912cf9
font_01_sfnt_off00012b06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B06 10192 bytes
SHA-256: b57e6f4adffc338beb462c5ba4de245959acc630fc1b50442d95d32ec68007ce
font_02_sfnt_off000141f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x141F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1