Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9d898f2e67193b7…

MALICIOUS

PDF

92.1 KB Created: 2021-07-25 03:44:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: a645f61e501c6e100684c65ed74ecb67 SHA-1: 6a7d152892b8797be315da6d7214894d5202351c SHA-256: b9d898f2e67193b7ec69e808b9f576d2ca4c0632f0c77ac65004cfd175f73881
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Static analysis revealed the document functions as a link farm, with numerous embedded URLs pointing to compromised CMS upload directories and disposable hosting. These links likely serve as a lure to direct users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/835a629641d44aa6aadaa398d22ae364/94636092370.pdf In PDF document text
    • https://sikanderajam.com/Robinson/ckfinder/userfiles/files/wabusixelelatuvuj.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be9752c91b7---bokavibuluduken.pdfIn PDF document text
    • http://asztalosweb.hu/userfiles/file/wonekaraviwutofegapavifi.pdfIn PDF document text
    • https://bankubezpieczen.pl/userfiles/file/texorenodisut.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160814fd333bc9---zadobivamijarugomata.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a6bc35cb67a---zokarerusotelavugi.pdfIn PDF document text
    • http://nusamulticentralestari.com/Uploads/userfiles/files/86410590930.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/1b7129e4ccdfff7c804b68102b7f2ea2/30968404023.pdfIn PDF document text
    • http://whalesart.com/uploadfile/file///2021051900503549.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606efdd3bb572---pevuwamifesokoj.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/3aadc4f8920cc7f8d793192ff66bd971/78285046006.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ac90fb8f6c5---1055930960.pdfIn PDF document text
    • https://nffcd.org/userfiles/files/renatav.pdfIn PDF document text
    • http://hungbuloon.com/media/ftp/file/nudiberetizujibirewudebos.pdfIn PDF document text
    • http://perfekttorun.pl/pliki/99616626435.pdfIn PDF document text
    • http://salon-urody-bellis.pl/images/file/tanumeberu.pdfIn PDF document text
    • http://navigator-nsk.ru/userfiles/file/gobigudi.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/6a9c50128dac71ab802a5877688a777e/xidafuporu.pdfIn PDF document text
    • https://digireg.nu/upload/77743131766.pdfIn PDF document text
    • http://namlongprojects.com/images/uploads/files/42082372366.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/0ad07e665dc32200a00d499d2cb354d9/71204451267.pdfIn PDF document text
    • https://bjjewels.net/nbloom/fckuploads/file/77196712913.pdfIn PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/e2a90e6fb15c9a48917cc79923c58e64/70047218343.pdfIn PDF document text
    • https://vestol.bg/files/file/sivezalupoxebo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=to+live+in+the+borderlands+means+you+essayPDF 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_off00010370.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10370 17164 bytes
SHA-256: 0bb5a008cfb641c44319b3cc78216b4ecc98b2516bc60f779285ab3add52bb6a
font_01_sfnt_off00012f5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F5F 10896 bytes
SHA-256: ee66f6f86b41cebd06fe8341f304f4b1b3f9ba198614ea4d2d2feb153b6fefc2
font_02_sfnt_off00014866.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14866 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1