Malicious PDF — malware analysis report

Static analysis result for SHA-256 43752820d5dad03f…

MALICIOUS

PDF

127.6 KB Created: 2021-07-31 22:51:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8d78c11223beafdce29271193d026e04 SHA-1: 7f3e4f6af9da9ac10a1c4d415c267fdd7cf60732 SHA-256: 43752820d5dad03f812af278c0eae606a986026457e71ece21127cac3b64f8d3
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The PDF structure and link farm characteristics point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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 https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/084e2tbal4r5gog2ngovi30286/35293612370.pdf
    • http://vtdsbinhthuan.vn/public/uploads/userfiles/file/jesitazajikegufozufa.pdf
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/38173364027.pdf
    • http://henskeschildersbedrijf.nl/upload/97495078331.pdf
    • http://marketherballize.com/ckfinder/userfiles/files/tebifitademeketem.pdf
    • https://alshuka.ps/ckfinder/userfiles/files/juzitamimagi.pdf
    • http://accessiblevehicleservices.com/userfiles/file/liregefafitip.pdf
    • http://volamtuyetthe.com/userfiles/file/seforowatimatodowisadage.pdf
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbff616861---vaxefefovisesipesexewat.pdf
    • http://noithatdangcap.vn/app/webroot/uploads/files/45918734210.pdf
    • http://immodraft.nrw/images/architekten_agentur_images_/file/71654145330.pdf
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608541b23d77f---guzirezaxaxeg.pdf
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a42424e483b---jefemibukemogubif.pdf
    • https://brandonsmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/bfoig04ajgpu62i6llfje8clk6/fifanimukinanoxula.pdf
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a34a6e7b9c3---40752451546.pdf
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/161013f51a2e11---46258419926.pdf
    • https://cakesandcupcakes.net/userfiles/files/nevabusineronuwor.pdf
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f6504f33ab---80473336577.pdf
    • http://dohertylaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/74936472694.pdf
    • http://collectifff.be/imgdb/accueil/files/90754659320.pdf
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/29056c9eeff32e8e6267153919d65403/29474694207.pdf
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ec4d4554948---domilefegopewijadivuler.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=ejercicios+resueltos+descomponer+en+factores
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000191b2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x191B2 16792 bytes
font_01_sfnt_off0001a9c9.bin
a72b5075fc07fb2e1c35a19f7de87a57c53921f20e929fd7eec6abcfff8f7084
pdf-font-stream PDF embedded font (sfnt) at offset 0x1A9C9 10992 bytes
font_02_sfnt_off0001c33d.bin
b11e4819ef2fd8838c7deb6233d295168d0d98301a7c02ff1c8dc10d00823341
pdf-font-stream PDF embedded font (sfnt) at offset 0x1C33D 18824 bytes