Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f419512a2c32d0f…

MALICIOUS

PDF

88.8 KB Created: 2021-06-27 23:48:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 36bcbfa70083a18901fae1ad0f97c853 SHA-1: 469edf42a865003fef6aa7561f69aafc70c7dd97 SHA-256: 5f419512a2c32d0f49801e005e0dcb5288ee52fed5ae3dc317fc11d261c51419
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 multiple compromised WordPress sites and other domains, indicating a potential distribution point for malicious content or phishing lures. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, and the document body was unreadable, so the primary evidence comes from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://ocw.tw/uploads/files/8633228768.pdf In PDF document text
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/f4cfac8dd94c44637ab135cfef62d716/kufekabinoxiwepediz.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160a59dddc7e00---59968295714.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/6f23cf80eb94f581e4ca3982f4136d27/fapesogapedisukiwoz.pdfIn PDF document text
    • http://ballarioarchitetti.eu/userfiles/files/mexosebugusikok.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/160b06a5ae7651---juzezudadon.pdfIn PDF document text
    • https://narimasu-chintai.net/jcfiles/file/notexetam.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16096c5ec8de58---41537503254.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7c9a982696---fotimoxepegu.pdfIn PDF document text
    • https://luxmarketing.agency/wp-content/plugins/super-forms/uploads/php/files/95942ls18jrca18d8kombekviv/xubisogujojukemapur.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160711be940a87---75406504811.pdfIn PDF document text
    • http://igorodstore.ru/files/userfiles/files/74616723110.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/3dae78ca82a9a3c5593399df097a9be9/51037831572.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160cb23fe47e50---39767232073.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a77c03c93d7---bejebazevazafosogezibi.pdfIn PDF document text
    • https://ebooksweb.net/files/file/65242839331.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a133a67e51c---89766678317.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d601e9da6e1---38882661510.pdfIn PDF document text
    • http://gibisch.info/files/files/58199527974.pdfIn PDF document text
    • https://bauarch.bg/files/godubas.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/fagakusetotile.pdfIn PDF document text
    • https://www.spreefahrten-berlin.de/wp-content/plugins/super-forms/uploads/php/files/n3tol9e7hm36v27form5jd5vsu/45851820853.pdfIn PDF document text
    • https://aneri12.eu/res/file/45124202729.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160708ced4f792---52548890484.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=easy+english+riddles+with+answersPDF 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_off0000f908.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF908 17108 bytes
SHA-256: 19233e779f62230507e454e34d5662625f92fc6725cc6d9747ed46dee99d8657
font_01_sfnt_off0001258f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1258F 10592 bytes
SHA-256: e059b5326eda05943f55f26a81bead6d44724457dc35f1cb041838781a7b3de5
font_02_sfnt_off00013d87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D87 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1