Malicious PDF — malware analysis report

Static analysis result for SHA-256 7933456e3504ef7a…

MALICIOUS

PDF

77.6 KB Created: 2021-08-09 00:13:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: bb89d13fbd3fb8f722b32700fbeb120a SHA-1: 1cccf0e164188ce50244ffa7c393a81a9975029c SHA-256: 7933456e3504ef7af9b002abe2d69c257b534c83d5408d26975abafca2549553
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 other PDF files hosted on various domains, many of which appear to be compromised CMS uploads. The ML classifier strongly indicated maliciousness, and the structure suggests an attempt to manipulate search engine results or distribute further malicious content. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://caratow.eu/userfiles/file/sunorutemev.pdf In PDF document text
    • http://arcadia1973reunion.com/clients/3/33/33cb7023d77084166ed027ca16b579b7/File/74936817877.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/xizix.pdfIn PDF document text
    • http://xn--80aafkqcanfpgnhbng3b5i9a.xn--p1ai/pict/file/96380894398.pdfIn PDF document text
    • http://www.mustwalge.ee/data/content/files/69758781736.pdfIn PDF document text
    • http://aite-materials.com/upfiles/file/14061860311.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/r5p4kka6hsedq0f719cp72pngc/3380552857.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608fe44d34949---vaxikepevijosekulixobo.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/9ev3onhrmj2hgf7b82bkcgomm1/99776962515.pdfIn PDF document text
    • http://bsl-trans.ru/admin/ckfinder/userfiles/files/nikimuje.pdfIn PDF document text
    • https://aadharshilaschool.org/userfiles/file/wawivawutiven.pdfIn PDF document text
    • http://www.me.ntou.edu.tw/ckfinder/userfiles/files/20210804_084932.pdfIn PDF document text
    • http://myrbacken.se/login/ckfinder/userfiles/files/9220009406.pdfIn PDF document text
    • https://gyandeepjkss.org/userfiles/file/vokigotozut.pdfIn PDF document text
    • http://irinaburmistrova.ru/files/lazojekusurimamin.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/12dc524d582bc7aa320cff0227974272/pebabosazolewino.pdfIn PDF document text
    • https://takeorders.online/wp-content/plugins/super-forms/uploads/php/files/lirtoqvutg9b3l5rg97v19r66d/dorevufulazulilazu.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/028af9f0726d85bfd1cd8651ebde7a7c/napedojikoje.pdfIn PDF document text
    • http://southport1969.com/clients/861680/File/foxekerokutexuk.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/6d5d90bc50d592922c2848b3180154d3/momekemejibale.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/9ebe7c2dcfaf8004513cc75947e485cc/36558972056.pdfIn PDF document text
    • http://rayer.cn/d/files/liwidinusupavirizefube.pdfIn PDF document text
    • http://pokemom2.com/uploads/files/1791521659.pdfIn PDF document text
    • http://udmvdpo.ru/images/files/17961719521.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/b5b07d4167141aeebfbc595dfd7d30de/930089689.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=formulas+de+estadistica+inferencial+en+excelPDF 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_off0000c7ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7EE 10816 bytes
SHA-256: 6781c6ff639a014af24f880f1465036494af578aa106196a3f2a7261be35a744
font_01_sfnt_off0000e0db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0DB 17596 bytes
SHA-256: 3ef2e18dbc8ca4c8467be093e4c1c6a9f092489e0192f899b07d74a907718819
font_02_sfnt_off00010db5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DB5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1