Malicious PDF — malware analysis report

Static analysis result for SHA-256 08c9fba750965fc7…

MALICIOUS

PDF

68.1 KB Created: 2021-05-23 04:32:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 757e4910f8cb34905b1674611ff43215 SHA-1: be586351e1203134d73d3ab5ece9035b2a5375f8 SHA-256: 08c9fba750965fc761b6c3e394cb8e5512d8007a8e1ea984afea331e57721ede
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites, suggesting a link farm or redirection scheme. The ML classifier strongly indicates maliciousness, and the presence of external URIs and link farms on potentially compromised CMS uploads points to a tactic of distributing traffic or hosting malicious content indirectly. No scripts were extracted, limiting the analysis of direct payload execution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://coretry.ru/uplcv?utm_term=dragon+ball+z+ppsspp+game+file
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/g3rqom7usugdniko385gd411b6/8101795676.pdf
    • https://beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/114ab8678f3b2d0f4731116abfd60ae5/4691797444.pdf
    • http://birnagarcollege.in/userfiles/file/23455023703.pdf
    • http://kaupa.cz/userfiles/file/zutiripubasevipe.pdf
    • https://lightingsystemscol.com/wp-content/plugins/super-forms/uploads/php/files/d572f0241fd6322995ec819352b5b725/41824397603.pdf
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090e7faf162f---fexavigonelokamot.pdf
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e1fc7d3111---noxugafazuroxubigamepupeb.pdf
    • https://laser-arena.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9b1a3818a---bizomorubenuvigeva.pdf
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608950bb14ae9---kuzakibagajinawu.pdf
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/dlcstbjr2771d2nephmeo8vufk/80730707186.pdf
    • https://www.scilights.com/wp-content/plugins/super-forms/uploads/php/files/b954dd08de6cd2df03b202dc7d710387/8501294469.pdf
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160799d7e631fe---45921855185.pdf
    • http://adria-ex.com/images/blog//file/xanoxigewanewit.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/0b894295bcc24cf00fad3c9bc6d44dba/57786030142.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cfc7.bin
4f726b81c2931f53676bf9c56f9782e9f6a273d7f76f30c360bf7ebac19cff9b
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFC7 5412 bytes
font_01_sfnt_off0000e226.bin
03f3fc6526eab7f356c7d5e97fb5a403901fe523fa7c9f3b594a716351e5e071
pdf-font-stream PDF embedded font (sfnt) at offset 0xE226 10476 bytes