Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4c0834a15a08a53…

MALICIOUS

PDF

68.9 KB Created: 2021-09-28 21:51:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: eeeaa17f088428c389132bf164941790 SHA-1: 5ad4a405867e9ddda97bc5d5cfd6bdef8eeec127 SHA-256: f4c0834a15a08a5308229ad4091f2947d3227c941897fb50ca3497f8c2b2befb
156 Risk Score

Malware Insights

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

The file is a PDF containing numerous links to other PDF files hosted on various domains, many of which appear to be disposable or compromised. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO spam. The embedded links suggest an attempt to direct users to potentially malicious content or to manipulate search engine rankings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://anpo.vn/upload/files/58137773889.pdf In PDF document text
    • http://xinyuemu.net/assets/202109/files/20210919183854834640.pdfIn PDF document text
    • http://pomocnaukowa.net/Upload/file/69447122006.pdfIn PDF document text
    • http://devitohomesorlando.com/userfiles/files/20014543027.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f4987207b6---jakazexevagib.pdfIn PDF document text
    • http://bellina.pl/userfiles/file/bogazumiresinuxisipe.pdfIn PDF document text
    • https://namphuctourist.com/userfiles/file/3071315878.pdfIn PDF document text
    • http://associatedreclaimed.reclaimedoils.com/userfiles/files/januzezujiwufi.pdfIn PDF document text
    • http://unsersohn.com/images/file/8896043877.pdfIn PDF document text
    • http://sanyosushiglendora.com/uploads/files/43739186851.pdfIn PDF document text
    • https://hocaukhudothithanhphogiaoluu.com/asset/site/files/31198332515.pdfIn PDF document text
    • http://mega-treid.com/userfiles/files/sexepak.pdfIn PDF document text
    • http://willbramephotography.com/nabopevibajodirukomi.pdfIn PDF document text
    • http://potlista.com/file/files/48457966305.pdfIn PDF document text
    • https://kapefashion.com/files/files/jezinokitegiruluwix.pdfIn PDF document text
    • http://thienminhgroup.com/uploads/userfiles/file/30732916712.pdfIn PDF document text
    • http://penzion.sarmo.cz/Images/file/ketilodo.pdfIn PDF document text
    • https://lmbri.com/WYSIWYGImage/file/22098002874.pdfIn PDF document text
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/161407d4ec9f94---seperijedifumeminolido.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/3a48b185fe7fcc7cc49ac0e68091f5cd/41932918947.pdfIn PDF document text
    • http://ji-tien.com/userfiles/file/6961462091.pdfIn PDF document text
    • https://bienenaktuell.com/sites/bienenaktuell.com/files/file/71182932593.pdfIn PDF document text
    • http://danchrisjewelry.com/userfiles/file/43541570775.pdfIn PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161441fdf9ce2b---77695899804.pdfIn PDF document text
    • http://arsvet.ru/img/upload/jawuwisujab.pdfIn PDF document text
    • http://fuhua.tumujike.com/assets/upload/files/202109170946585317.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=god+of+war+ppsspp+gamePDF 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_off0000b10d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB10D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c924.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC924 10628 bytes
SHA-256: a9e8fdac9fe96a6fcdc2e0d3693733c0d9cfe3c8dc7d6f94531cd73bf1ed681d
font_02_sfnt_off0000e15c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE15C 14672 bytes
SHA-256: ec4b72065316865dea61152c22bfb7aa3c3f3d7c815c0655f58d8e4fb11dd742