Malicious PDF — malware analysis report

Static analysis result for SHA-256 71e7a23fb1581852…

MALICIOUS

PDF

86.6 KB Created: 2021-06-30 21:23:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 35c1aa56831ffcbbba752cc3098b7918 SHA-1: 4ca1b4fc9569ee4849b4906f950b92bd2cddf0c0 SHA-256: 71e7a23fb1581852466b17da2ccd37891b60ee1dbfa807d52d174abf18517823
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier strongly flagged this PDF as malicious, and the presence of external URIs and link farms on disposable hosting further supports this assessment. No scripts were extracted, but the structure suggests the PDF is designed to lure users to malicious external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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=brother+8065dn+manual PDF link annotation
    • https://bodwellassociates.com/wp-content/plugins/super-forms/uploads/php/files/0fc6d8ef615602d57917795b69f18aee/vupuruxenam.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d6240171dcb---6068800054.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5b138a8016---65643037710.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/83312448709.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609e70ed63bcc---9502889062.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/r9j2mq9sfmgg0i2ahegru3n2ad/96530321665.pdfIn PDF document text
    • https://tonwen.org/userfiles/file/pafumemejijos.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607053e6e09f2---mawuponawasupuk.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/ec4919436cb264ecd7f37971319818b0/67311342834.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/160a8ef3fe64e6---62537679474.pdfIn PDF document text
    • https://vandolderskb.com/images/usr/fumologus.pdfIn PDF document text
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/763e8fb6aee0837c3c071ff9f09ab613/lotosukuninef.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d20205f3287---72023734775.pdfIn PDF document text
    • http://wooshin.kr/uploaded/file/1406035512609a592a0eaaf.pdfIn PDF document text
    • http://bike-aholic.com/UserFiles/file/18092544113.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/98295334103.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1607e220a05920---rixevetizewimuveludinito.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d9668dc376---zemotarew.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa401674d1---80826156551.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_off0000ea21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA21 11040 bytes
SHA-256: e441bd57c5289bc9fb21ecfa3028eff687868eb37fa621d1d7ba433534286be7
font_01_sfnt_off000103b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B4 19660 bytes
SHA-256: 153d262523f2e3d90354c7a0ec1471820d5fb7ad25dfd0fec11fb607b2f4606a
font_02_sfnt_off000135a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135A4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1