Malicious PDF — malware analysis report

Static analysis result for SHA-256 9135691a3936b21e…

MALICIOUS

PDF

73.6 KB Created: 2021-09-09 14:06:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2818126aee04bee1adf413a1bbd16e7c SHA-1: 6804374281bc2609ef02ec634f400635ddf7a756 SHA-256: 9135691a3936b21e1d223d0fce809462a263bbf5e7900a154607eb4102689bd8
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and unreadable, preventing a more specific analysis of its lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://kotolantopeni.cz/file/filodi.pdf In PDF document text
    • http://www.w.radeton.cz/ckfinder/userfiles/files/tubaxetipexerogudafap.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138138e4ead7---kabinerofagajufotikapiv.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/75cad705d4bda6d24ceccc4488ce3c84/12892368311.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16137e35087ec6---tipawasuvojipajula.pdfIn PDF document text
    • https://esterkins.de/ckfinder/userfiles/files/35928059056.pdfIn PDF document text
    • https://wilocom.ro/ckfinder/userfiles/files/39935061350.pdfIn PDF document text
    • https://senarathgroup.lk/assets/media/file/xikomojovuwajuzigaj.pdfIn PDF document text
    • http://yurisolomko.com/userfiles/file/5335145046.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/wovozu.pdfIn PDF document text
    • http://www.hzkontejnery.cz/ckfinder/userfiles/files/5438778589.pdfIn PDF document text
    • https://kapefashion.com/files/files/ginivonutidawivesibezuset.pdfIn PDF document text
    • https://gfwofficial.com/ck_imgs/files/60188335695.pdfIn PDF document text
    • http://phone-server.com/userfiles/file/fevexoxoxixikuvite.pdfIn PDF document text
    • http://kommunikator.nu/demo/userfiles/file///63261785234.pdfIn PDF document text
    • http://lideparts.com/userfiles/file/1630643529.pdfIn PDF document text
    • http://balmybnb.com/t/tutorfirm/uploads/ck/files/nojumipineli.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/161325c62030d9---7325365046.pdfIn PDF document text
    • http://www.armstrongre.com/files/files/zasimolopuwin.pdfIn PDF document text
    • https://mayphotocopydogia.com/upload/files/66530367646.pdfIn PDF document text
    • http://emilybarnes.com/DEVELOPMENT/VERSIONED/emilybarnes/trunk/sites/default/files/file/49469074579.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=python+crash+course+solutions+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_off0000bc5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC5A 10932 bytes
SHA-256: 7179b83a92d4cb18325e7e1d17318bab575ddfe5c932cf57c8f6c20077693450
font_01_sfnt_off0000d5a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5A7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000edb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDB9 16804 bytes
SHA-256: d77afc376dc48cf83a445daf115d391ee6de00c1172d1757c1fec4389b722dd0