Malicious PDF — malware analysis report

Static analysis result for SHA-256 135a782121edead6…

MALICIOUS

PDF

93.1 KB Created: 2021-08-03 10:46:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: fe7aa89fc6614a754590d196ba52385e SHA-1: b26dd2740d2a6948f142ce4f71853aa3b5d09eeb SHA-256: 135a782121edead634a39f4b2bf9cbb907c93f62e83b1963f65bcc5a55c33ac9
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to compromised WordPress sites, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the structure and URL patterns suggest an attempt to lure users to external malicious resources, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://catamma.ru/uplcv?utm_term=manualidades+para+el+d%C3%ADa+del+ni%C3%B1o+en+goma+eva PDF link annotation
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b74375137bb---bolanebanizazuxi.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/160766ce471a24---57194312243.pdfIn PDF document text
    • https://vidolamerica.org/wp-content/plugins/super-forms/uploads/php/files/1765b0040caa60bb87cff394690e9c69/80025108851.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/fc292b5210d1beeeeb124808f78595f0/79658350817.pdfIn PDF document text
    • http://obchodsezlatem.cz/upload/files/wuzogoluputu.pdfIn PDF document text
    • http://mosvag.ru/img/lib/file/55019489209.pdfIn PDF document text
    • http://flatadministration.com/uploades/fckeditorfile/jikogom.pdfIn PDF document text
    • http://hobbstownis100.com/clients/6/66/66141d04a4341350d76ae3a38785cb5a/File/90314495873.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/fa383065ac328714f7594b44169186ba/15723711455.pdfIn PDF document text
    • http://fipjp.com/userfiles/file/66276796110.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/5620bd1d42280326a4d21f38b3340454/xalokojugevutoferugon.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/71157c100be56f530f559f1706502ec4/27697340589.pdfIn PDF document text
    • https://pasarant0g3l-turbo-h1t.com/contents//files/35524662384.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a13fbbec019---21545214067.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/c99d92d26a7613752c73c23ee2b4a11d/55155100835.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210524105307614.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/16078ab359f6d3---bedumogodezerakinobegawo.pdfIn PDF document text
    • http://fmafirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/15412161166.pdfIn PDF document text
    • http://edwardfmcgintypa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/keviti.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cce86a1bd2---1155412255.pdfIn PDF document text
    • https://dermatologie-francophone.com/userfiles/file/boket.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/sikuwil.pdfIn PDF document text
    • 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_off000104ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104EA 18148 bytes
SHA-256: aab8d31b758fffda3367bbcded934eccfd4bf05b646628641e8c14e52b95a6e6
font_01_sfnt_off0001324e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1324E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014a65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A65 11064 bytes
SHA-256: d409b884da3f20546a994fb76937cc5993c88d16629820cc0ea1d135a704905d