Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b6639a1fcb2b317…

MALICIOUS

PDF

73.6 KB Created: 2021-09-12 19:27:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 0e2ecca8201025af5eb35aed882c88ff SHA-1: e7515957bb22b67d5f9f10b1972ad0783278e2fd SHA-256: 5b6639a1fcb2b317dd3edda397f322040a1ae460713fc54af18a2ccd8b40fdf4
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, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting it's used to distribute further malicious content or phish users. The document body was unreadable, but the presence of numerous external URLs strongly supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 http://pvvc.cz/files/16217821067.pdf In PDF document text
    • http://kunas.lt/app/webroot/uploads/files/navinusokogemiwitos.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161344ea79392c---xoxesovuxajatese.pdfIn PDF document text
    • http://travel-door.com/userfiles/file/vitedorinoxeverojapefejop.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/16136ace3735c5---nomuwoxujuzewedamabar.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137583525a7f---41163566503.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/0ce424f110358d1b05fbfbb17ea2351a/lukewanoge.pdfIn PDF document text
    • http://furniture83.com/upload/files/52735513949.pdfIn PDF document text
    • http://www.szphotar.com/admin/img/files/fidixakagavoz.pdfIn PDF document text
    • http://kaizenlife.com/ckfinder/userfiles/files/sokomo.pdfIn PDF document text
    • http://www.musicboxpiano.com/contentfiles/49569519327.pdfIn PDF document text
    • https://ijtm.in/userfiles/file/vudurotuganitot.pdfIn PDF document text
    • http://finemetal-cn.com/upload/files/zurijovivo.pdfIn PDF document text
    • https://matao.ro/app/webroot/files/userfiles/files/jadunevarabewipununafuno.pdfIn PDF document text
    • http://studiolegalezullo.eu/userfiles/files/14751884040.pdfIn PDF document text
    • http://pactolous.hu/upload/file/pulilapekutikojarexutaj.pdfIn PDF document text
    • http://misr-consult.com/userfiles/file/18500567130.pdfIn PDF document text
    • http://hatdesechia.com/storage/ckfinder/files/wuxezukopa.pdfIn PDF document text
    • http://arucax.am/user_images/file/42406520172.pdfIn PDF document text
    • http://www.recko.ru/ckfinder/userfiles/files/wopomexubafuzel.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/13009222865.pdfIn PDF document text
    • https://khmernative-rice.com/userfiles/file/60274962678.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=emote+ml+apkPDF 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_off0000c130.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC130 10024 bytes
SHA-256: 33ba2c4494dd78a1f50156126802dfa3f3190c573c718451714632ecec02bdd5
font_01_sfnt_off0000d776.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD776 16400 bytes
SHA-256: 22e8c21a35f8f4ded0ed66e12c5a45ac8bb536065a0f1d71b5471d2bccaeb085
font_02_sfnt_off00010183.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10183 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1