Malicious PDF — malware analysis report

Static analysis result for SHA-256 b504371937b164e9…

MALICIOUS

PDF

97.1 KB Created: 2021-07-04 14:07:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 77577d9d59e2055231d57685991735fd SHA-1: cdbb07fee46d544f5980be09f4d65ec2a9abcfde SHA-256: b504371937b164e96ec7a058f16dd218373fbcb64e869ca88597d38efcbdd235
96 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm or SEO manipulation tactic. The ML classifier strongly indicated maliciousness, and the structure aligns with hosting potentially harmful content or redirecting users to malicious sites. No scripts were extracted, but the heuristic firings and URL patterns are sufficient to assess the likely attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 5

  • 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://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/mm36fi082esdpovdll7ppbvqe5/63707093912.pdf
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/h9ifjr338q91v3mgn54ufvogne/71956272925.pdf
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2be3449b2c---65718383294.pdf
    • http://cnokorea.com/userfiles/file/fugafobuzakubunin.pdf
    • http://alibabashipping.com/userfiles/file/webusekadirigire.pdf
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b11fd509531---nurejetiwevuxujusoso.pdf
    • http://cokhibaosang.com/media/ftp/file/86191475792.pdf
    • http://wallsfamilyreunion.com/clients/876683/File/revakepowowaja.pdf
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce69523f4dc---gipejepajin.pdf
    • https://e-uchebnici.com/img/file/83203224511.pdf
    • http://www.ambredore.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2902d6177c---24178021203.pdf
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fcc1d09c1b---xenomiveguzefi.pdf
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2d96321c2b---gonuralavu.pdf
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b8158c3c6e---pajezigigarubegisewojajis.pdf
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca10d353e5---20576180299.pdf
    • http://shhs69reunions.com/clients/e/e9/e92da0bc0099326815942f81a5c18dfc/File/silolumaz.pdf
    • https://arte-salon.ru/upload_picture/7465458110.pdf
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/3kmhs911dhhmaeaq6q32g24cjb/60390300235.pdf
    • https://uniqrelation.com/userfiles/file/muvugaze.pdf
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/076fa543943b6d14f2647a6dca43c70d/70609501193.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=types+of+mythical+creatures
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • 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_off00011587.bin
b915d64995507f8360350c8ca4f997cb9d7955f512f72bc7cf667df540548d00
pdf-font-stream PDF embedded font (sfnt) at offset 0x11587 10820 bytes
font_01_sfnt_off00012e8e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E8E 16792 bytes
font_02_sfnt_off000146a0.bin
271393cdd1d499a7bc3e10be4fa392cee5e5d02271459d01e5bf50dffded3ccb
pdf-font-stream PDF embedded font (sfnt) at offset 0x146A0 20100 bytes