Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8cf7536d1ae4599…

MALICIOUS

PDF

80.0 KB Created: 2021-08-08 07:04:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 928b1c855cb76a3acddf1bf62928fca5 SHA-1: 94b16274ba165062092e17b797da1cc93b1ab5b3 SHA-256: f8cf7536d1ae4599c30ecdcfb5f16c76ade61a149fc302f1c8807772026af7b4
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the analysis relies on the URL heuristics and AV detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/711524503e74412202d4908f2dac8309/xibimejoz.pdf In PDF document text
    • http://sampsonancestry.com/clients/d/d9/d9bd9208c4e45de01aa31840e3a8c66b/File/menosaturumewij.pdfIn PDF document text
    • https://study4student.com/cache/fck_files/file/71389000116.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160fe2b4e73971---zubabipe.pdfIn PDF document text
    • https://iuoshili.com/upload/users/files/8852414015.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16082430e6a8cf---tonevonaxavolaritesomuf.pdfIn PDF document text
    • http://jpbullies.com/clients/2/2c/2c827f09d77a589c2c5c7da8c033a3f4/File/nodakoxifogidorikilawofok.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/ff1a602a4d90c7d6868a991a112e98ab/lijoruxuvimubamaf.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075506592d44---rufaturixekisoseduj.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/fdceb13f8f43ebf3fea8ede4c94d0c5a/potadudojujawug.pdfIn PDF document text
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ed80d73b72---15056817608.pdfIn PDF document text
    • https://flyingfish-stay.com/userfiles/file/57463888880.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/a83cdiq0t60l666kpbh5d2nck4/2755890495.pdfIn PDF document text
    • http://vankouwenenmastop.nl/UserFiles/file/sejisibolexu.pdfIn PDF document text
    • http://sorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/59308310174.pdfIn PDF document text
    • http://metapolar.hu/tmp/33350195676.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/66e54c430683b8692a5219573a21aa93/kixufisidab.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/f052ca132e02b84918dc2b7dddb2df54/84503468318.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/79f71e8317f7da8fd4d63ea13fdd11c3/lunovexeliwabijakulude.pdfIn PDF document text
    • https://mobiligennari.com/userfiles/file/82771593649.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/40e3f8614c08d1bf7a951948bc806969/59173919763.pdfIn PDF document text
    • http://skisun.it/userfiles/files/kumikumufidorixemedimope.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a59929758f---24633106007.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=entre+el+diablo+y+el+profundo+mar+azul+en+inglesPDF 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_off0000d204.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD204 11236 bytes
SHA-256: 7660d618fd00b37e12b2751f3bd6e639e1e5b81e03fd32e3e0b1a3ed9002787f
font_01_sfnt_off0000ebec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBEC 17836 bytes
SHA-256: 3092efec569597739dd60974826e03ab5e5f624330bc05464e24dc961270e250
font_02_sfnt_off00011944.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11944 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1