Malicious PDF — malware analysis report

Static analysis result for SHA-256 18f6e5f910931ad9…

MALICIOUS

PDF

72.0 KB Created: 2021-09-12 22:48:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 97fca346ca3f96dc9e1dce3c5d361c8c SHA-1: 04ccfaa55d5a78ad1f1ac1e9bbb3cad6cdd637f6 SHA-256: 18f6e5f910931ad95a424f49a0c55ab3e996bd37e81406be4b87fbbc85c38a88
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous URLs, many of which point to compromised CMS upload directories, suggesting it's designed to host or distribute malicious content. The presence of a link farm on disposable hosting further supports a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9941

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://thucphamtruongxanh.com/Upload/files/10347192127.pdf In PDF document text
    • http://milkyway-vn.com/upload/files/96472730164.pdfIn PDF document text
    • http://thuexe7cho.vn/upload/files/rewavowigi.pdfIn PDF document text
    • https://buyafranchise.org/files/files/vajavojerisenetovuvutu.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/62809492770.pdfIn PDF document text
    • http://joyearland.com/ckfinder/userfiles/files/vudojirapexubagemopelusip.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131e2ffcf27a---85024156883.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161390a295288b---74038006584.pdfIn PDF document text
    • https://siltri.com/fck_upload/file/4658751840.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb735c1a8a---bekep.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/161390fc1061b4---gavaletoloxadadeg.pdfIn PDF document text
    • http://ciaomamma.hu/editor_up/manojubo.pdfIn PDF document text
    • http://kayamedbursa.com/userfiles/file/33910590182.pdfIn PDF document text
    • http://4rrecycle.com/files/file/pisikaxi.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/1613d277499647---47621414597.pdfIn PDF document text
    • http://studiopiergentili.it/userfiles/files/vagukafidomif.pdfIn PDF document text
    • http://se-ty.com/uploads/userfiles/file/22816552575.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161398d22e9d71---22406743099.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/puzogewojupobinuz.pdfIn PDF document text
    • https://crbz.ru/userfiles/file/4287750721.pdfIn PDF document text
    • https://chokysitohang.com/Uploads/userfiles/files/23150937787.pdfIn PDF document text
    • http://inannamsao.com/uploads/files/jenezamatabiwix.pdfIn PDF document text
    • http://tjsijiqing.com/ckfinder/userfiles/files/2021/0909/86fea24d6f3b11d52fedff53624e55fc.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=q+desire+2017PDF 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://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_off0000b8f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8F5 17376 bytes
SHA-256: d503c7e1c9ea166a46ff61785e92b879af638104fe35a0497aa69763c9b0eb6d
font_01_sfnt_off0000e678.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE678 10116 bytes
SHA-256: d1df18ec648ab3e03921f2903168efe81de5a6afc0c39dd973ead38765eaf063
font_02_sfnt_off0000fd50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD50 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1