Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bc7c1d6bfbe1161…

MALICIOUS

PDF

87.9 KB Created: 2021-06-30 00:05:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 145cf1d8c6e1e7a44d62a681b7070e02 SHA-1: 9ba6c3e794e7a82f80626366bb5477819d08d2b6 SHA-256: 4bc7c1d6bfbe1161fca9f4de85fad2e1898f0ba01db37102cadd6bd8199f4adf
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs pointing to compromised WordPress sites, indicating a link farm designed to redirect users to malicious content. The ML classifier strongly suggests malicious intent, and the structure of the PDF with multiple distinct hosts and UTM parameters points towards SEO poisoning or phishing lures. No scripts were extracted, but the primary attack pattern involves directing users to external malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://allytemp.ru/uplcv?utm_term=rocky+mountain+spotted+horse
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/p24drff7ap956ebld880eoc36e/megetesanupuxalo.pdf
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160888e6eb9f1a---53316039617.pdf
    • http://sistersaviopublicschool.com/userfiles/file/13002591641.pdf
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e7916bc10f---vizojefi.pdf
    • https://alianzatours.com/imagenes/file/kulebudurel.pdf
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092c7635858c---xarodivupowenabubudires.pdf
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16093a287bf262---17396760542.pdf
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/3175a3c25b49fd5524a0cf50efb42a18/xiliwanez.pdf
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b18e7836f2d---ribirowebuzonesobij.pdf
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608567f9351e1---damojixijaw.pdf
    • https://baileyelectrical.services/wp-content/plugins/super-forms/uploads/php/files/ucll661604l0atpm03s6oelbp8/degobuvew.pdf
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/160d844c79ae12---lekunibovalivafiwolusi.pdf
    • http://cunningham-reunion.com/clients/7/73/7399477c88ef979e1ad3ac38e42cffcc/File/53970678775.pdf
    • http://zuche0551.com/upload/file/vedaliw.pdf
    • http://medica-eg.com/userfiles/file/82088695604.pdf
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/24d1409a912bfecb5e2240474aa92e98/xovugugaragat.pdf
    • http://www.macrolepidoptera.hu/userfiles/files/pisepopedokewux.pdf
    • https://angkortaxiservice.com/userfiles/file/15834373227.pdf
    • http://www.advokat.com/app/webroot/img/fck/file/wunosopuvagiz.pdf
    • http://saintthomasmonrovia.org/clients/a/a7/a774d5b45fc75aba9c6fcf07501e1e58/File/53077371749.pdf
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/4a99e2838c8989ffedb4482ea79b1b28/zedifukut.pdf
    • http://korean-school.hu/hangul/userfiles/file/60740298207.pdf
    • http://arablift.net/userfiles/file/kusozosevon.pdf
    • https://vieclamxaydung24h.com/upload/files/momup.pdf
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/160c8fc74e3a40---famekuzogevivazosufovo.pdf
    • http://ceomit.com/fckupload/file/busanatetekibimu.pdf
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16077b5085fa37---niponidesolafuzoxudoru.pdf
    • 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_off0000f448.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF448 16792 bytes
font_01_sfnt_off00010c5a.bin
d405f32c4b8b3a9c72e1c7af3dbad35a345fe53f8d9cd500e8b51a144344657a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C5A 16860 bytes
font_02_sfnt_off00013864.bin
3617d13cfc0030c7e5b19d5a2e12dc33a778710fe9e1e3ce3866cfe9f140d80a
pdf-font-stream PDF embedded font (sfnt) at offset 0x13864 11084 bytes