Malicious PDF — malware analysis report

Static analysis result for SHA-256 521cfc47d54f3114…

MALICIOUS

PDF

70.7 KB Created: 2021-09-27 21:25:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 12688dbae454a1762ee7a990c58bc159 SHA-1: b761fe737b27d7004ac1bdf9980e4b2958bbfed0 SHA-256: 521cfc47d54f3114d0d45bac0d3103afad49d36a8bda4caa0ab08d3d35f6bd60
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to potentially compromised websites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of multiple external URIs and a link farm heuristic suggests the document's primary purpose is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9926

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://ominocoibaffi.it/userfiles/files/torurupukolapuboweli.pdf In PDF document text
    • https://copab.tn/216mag.svn/uploads/files/nonekikapoguna.pdfIn PDF document text
    • http://ip-kamery.cz/files/file/69195035205.pdfIn PDF document text
    • https://lingchuanfloor.com/app/webroot/userfiles/files/pipexonesivobek.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161355e7fd0826---kerojeviru.pdfIn PDF document text
    • http://rickgrisolia.com/userfiles/files/95005841767.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/d6c5494fab71fbfa87cbf85e2b27a704/tedenevune.pdfIn PDF document text
    • http://letresorellebio.it/userfiles/files/91286841653.pdfIn PDF document text
    • http://olgapolyakova.de/files/files/52666972385.pdfIn PDF document text
    • http://lingvastar.z-i-g-z-a-g.com/userfiles/files/vexufosovo.pdfIn PDF document text
    • http://irvinenott.co.uk/ckfinder/userfiles/files/30652866358.pdfIn PDF document text
    • http://onlinevay.com/upload/files/52534302365.pdfIn PDF document text
    • http://petraifevronii.ru/ckfinder/userfiles/files/foluzowivujezibokemejeg.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/82d929907c3ed1a34d91d49e2379f384/79865675960.pdfIn PDF document text
    • https://fibaquitaine.fr/cebatrama/userfiles/files/viwabuwuturukoboji.pdfIn PDF document text
    • http://gruppocaminiti.it/userfiles/files/detowarujekajute.pdfIn PDF document text
    • http://j1medical.com/uploaded/file/gonuraji.pdfIn PDF document text
    • https://girisimhaber.com/uploads/file/batiwipomubonamadak.pdfIn PDF document text
    • https://fresh-cherries.com/ckfinder/userfiles/files/50722544604.pdfIn PDF document text
    • http://parcroyale.hk/userfiles/gabovexivo.pdfIn PDF document text
    • http://lawngo.net/fckfiles/6736110657.pdfIn PDF document text
    • https://n-tlg.com/files/file/34432736856.pdfIn PDF document text
    • http://ns.adobeIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=ps+touch+android+8PDF 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://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_off0000af47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF47 10596 bytes
SHA-256: 10dc1c366468cdb8a03ecbe2a081e5b04f978e3f36977ad7341b829113114ab6
font_01_sfnt_off0000c775.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC775 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000df87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF87 18760 bytes
SHA-256: 9883d891277f8780da36904dcbdf0ad2a9a9d96e28a2a2d7c485301a01cc527a