Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef59c8ff7137e5de…

MALICIOUS

PDF

68.5 KB Created: 2021-09-23 04:26:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b9f418be62e4eb0c36b032594cfe8678 SHA-1: a97d1bc90c3900230d72f07af041028a67d83376 SHA-256: ef59c8ff7137e5de900696fe730fd25155372c754be7625a2c8b33fc2697b3cb
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple PDF link farm heuristics supports this assessment. No scripts were extracted, and the document body was unreadable, so the exact user-facing lure could not be determined.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://lagrupacio.cat/file/78790051144.pdf In PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/l5bhud8e79vdh8ao5qvhiklnf0/82144122928.pdfIn PDF document text
    • http://viviapalermo.com/userfiles/files/96981435690.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/tagedelefu.pdfIn PDF document text
    • https://kompaspt1.com/contents/files/rovegonixepumatopapekorew.pdfIn PDF document text
    • https://nichebearing.leaddeehub.com/userfiles/files/zobupapu.pdfIn PDF document text
    • http://garmaclima.com/uploads/ckfinder/files/40882589318.pdfIn PDF document text
    • https://mediaget.ru/userfiles/files/6871316813.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bb2f8be605---fozixesugiku.pdfIn PDF document text
    • http://thomas-zigon.de/images/file/70090586285.pdfIn PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/zopodijeduto.pdfIn PDF document text
    • https://camphacement.vn/upload/files/varerulelotokadur.pdfIn PDF document text
    • http://zatexpress.com/upload/userfiles/files/mamixafabolegusov.pdfIn PDF document text
    • https://partroyfuneralhome.com/partroy/assets/file/towubopofutila.pdfIn PDF document text
    • http://johndanton.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/mirevegemojokufo.pdfIn PDF document text
    • https://artedeeducar.com.br/ckfinder/userfiles/files/somujoruma.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613e256e6ebab---zoxezemeridu.pdfIn PDF document text
    • http://terfigyelokamera.info/files/file/fuzedidobamovaniki.pdfIn PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/98704230511.pdfIn PDF document text
    • http://josephfellerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nanigadawufosenuw.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/245c77f77368643692edd3cdceaceeb4/73633468192.pdfIn PDF document text
    • https://distriparkbotlek.nl/userfiles/files/dulirobokivig.pdfIn PDF document text
    • http://hoanggiaphatland.com/uploads/image/files/80521650162.pdfIn PDF document text
    • http://learningkey.org/userfiles/6637849357.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=download+youtuber+life+androidPDF 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_off0000b061.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB061 14380 bytes
SHA-256: bf5f23ce0403ca47472e91b2ed8e8e4d27ef3038402f8b1de0384abaecc3c983
font_01_sfnt_off0000d434.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD434 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ec4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC4B 10620 bytes
SHA-256: e13dec4ad9d47cb924fff3387f6d007927a5c196c3893a7ba2d795f98ecd2def