Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5df7f5bb131c076…

MALICIOUS

PDF

93.0 KB Created: 2021-09-08 22:05:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e7936098d75c22d2e84add74930bd719 SHA-1: 059d796089c8fc084ee717997c3f7010e7983b01 SHA-256: a5df7f5bb131c076f4e01cca7f18c6060fd659cef026a111282903b566c6d9d5
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised or disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of a link farm and the use of compromised CMS upload storage are common tactics for distributing malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://stillwaiting.org/userfiles/file/kabaze.pdf In PDF document text
    • http://duocthientam.com/uploads/ckfinder/files/82677143670.pdfIn PDF document text
    • http://hk-sai.com/ckfinder/userfiles/files/sanijekonowi.pdfIn PDF document text
    • http://mebizstekla.ru/userfiles/file/takepi.pdfIn PDF document text
    • http://bfcy88.com/uploads/files/zibewemovagavelijep.pdfIn PDF document text
    • http://lnhaihui.com/userfiles/file/20210904052312_1635600244.pdfIn PDF document text
    • https://artasedanasingaraja.com/uploadfck/file/32715225234.pdfIn PDF document text
    • http://keystoparadise.com/userfiles/files/97491292873.pdfIn PDF document text
    • https://olterus.org/contents/files/kujivudogebutomitimoxuwod.pdfIn PDF document text
    • https://gdaniec.com/upload/files/mojonijagiragudexajo.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/woxub.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/69c180728ae08761c59e14da45e70dd8/zuribezuwe.pdfIn PDF document text
    • https://hlj-vibration.com/uploads/image/20210903/files/20210903035658.pdfIn PDF document text
    • https://santevita-bg.com/ckfinder/userfiles/files/duwanebilozovuzananejene.pdfIn PDF document text
    • http://bebaldebaran.eu/userfiles/files/danom.pdfIn PDF document text
    • https://aimtronu.org/userfiles/file/bokemoto.pdfIn PDF document text
    • http://pooq-design.com/app/webroot/fckfiles/file/fesiwofetusi.pdfIn PDF document text
    • https://stpm-sa.com/userfiles/file/33682098901.pdfIn PDF document text
    • https://stiff.pl/ckfinder/userfiles/files/lifezotoz.pdfIn PDF document text
    • https://sassanoproperties.com/FCKeditor/file/63236483278.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/6jj13o37s8hk7fo9168kpk1ifr/90285583640.pdfIn PDF document text
    • https://newsale.linyn.mobi/upload/ckeditor/pages/files/29740652776.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613585fee429e---bovipi.pdfIn PDF document text
    • https://tramtron.vn/uploads/files/files/patagojup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=kate+turabian+a+manual+for+writers+pdfPDF 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_off0001034e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1034E 18932 bytes
SHA-256: 4a012638b05d1aabe1a1894f6a13dd42fb20d350a3a87d3aa7265c139b77b5a2
font_01_sfnt_off0001347f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1347F 10976 bytes
SHA-256: d45e55c19587623a809958255c7ac072d8c8441a16e6306cdb54ae82105d2058
font_02_sfnt_off00014dcf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14DCF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1