Malicious PDF — malware analysis report

Static analysis result for SHA-256 94c0371387d37af2…

MALICIOUS

PDF

90.7 KB Created: 2021-09-23 00:45:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 13334abbceae7f98282bed869c8f98ec SHA-1: 94b9507ba52b0806e82b081156d9252158a2a547 SHA-256: 94c0371387d37af2435841eb3178fdde594e062d8d594dfb6edb8a6122773249
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The ML classifier strongly indicated maliciousness, supported by heuristics identifying the PDF as a link farm pointing to compromised CMS upload directories. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool, offering no direct user-facing content. The primary attack pattern involves directing users to potentially malicious external URLs, likely for further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://archism.ru/uplcv?utm_term=supernatural+trivia+crack PDF link annotation
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/j7dmbf2cmt7i8ajmonu4i42692/venawedepaxipel.pdfIn PDF document text
    • http://erainbowrealty.com/userfiles/file/28553383917.pdfIn PDF document text
    • http://amunt.madteam.net/ckfinder/userfiles/files/14106213356.pdfIn PDF document text
    • http://sipzip.com/userfiles/file/9816181985.pdfIn PDF document text
    • http://www.cda.org.hk/ckfinder/userfiles/files/7656251301.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613990958c924---venaragujabiguroretivape.pdfIn PDF document text
    • https://eltdb.com/UserFiles/files/lezipokebubofut.pdfIn PDF document text
    • http://huefpdf.org/upload/file/55673803470.pdfIn PDF document text
    • http://sns-russia.ru/userfiles/file/20928603573.pdfIn PDF document text
    • http://bamila.vn/luutru/files/84328332581.pdfIn PDF document text
    • https://yaslibakicisi.net/userfiles/file/2031318660.pdfIn PDF document text
    • http://geomanteia.com/userfiles/files/lusuvibixanebex.pdfIn PDF document text
    • https://aprenda-atdi.com/uploads/files/14955338800.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/sf99ec6r7eck13688spm9v156e/zakuvilaxozaba.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/122353036462.pdfIn PDF document text
    • http://acupunctuuryao.nl/ckfinder/userfiles/files/1797976663.pdfIn PDF document text
    • http://trunghungplastic.com/luutru/files/gijaxatu.pdfIn PDF document text
    • https://sealordhotels.com/ckfinder/userfiles/files/vaguxowem.pdfIn PDF document text
    • http://nigerseedindia.com/uploads/kuruwolokumebazibavikudo.pdfIn PDF document text
    • https://ochronaskory.pl/pliki_user/File/39615577093.pdfIn PDF document text
    • http://bfcy88.com/uploads/files/47157447539.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139e61761690---34898963598.pdfIn PDF document text
    • http://enjoyisagenix.com/ckfinder/userfiles/files/rumiwekavulovododozu.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_off000101fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101FC 16768 bytes
SHA-256: dcf27b3d6a1de7b1e13e3d98b56ebf68c6e099b4b134fcbedf3faa53d3ab852c
font_01_sfnt_off00012d2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D2F 10412 bytes
SHA-256: 5b2bb1a8c3819b06970291d7474c055751645d52d75ef0fd696fd32230263dc7
font_02_sfnt_off000144e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x144E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1