Malicious PDF — malware analysis report

Static analysis result for SHA-256 33e94b345b4e7160…

MALICIOUS

PDF

80.8 KB Created: 2021-08-17 11:06:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: c556243f22e29731165802525e9ead7b SHA-1: 2bbc7563da1f89b1515001414d0c9e82f4a01ef9 SHA-256: 33e94b345b4e71600d1f72d8f398f649508c8decf80e14fad3b5938478e35c79
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. The ML classifier strongly indicates maliciousness, and the heuristic firings suggest this PDF is part of a link farm, likely used for SEO manipulation or to distribute further malicious content. No scripts were extracted, but the presence of many external links suggests a redirection-based attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://chcial.ru/uplcv?utm_term=reaccion+de+combinacion+quimica+ejemplos PDF link annotation
    • http://camelliafb.com/uploads/files/202108140817578118.pdfIn PDF document text
    • https://weyergans-hcc.lv/userfiles/file/puditepu.pdfIn PDF document text
    • https://anctools.com/ckfinder/userfiles/files/96592882625.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608e08736577c---32369277075.pdfIn PDF document text
    • https://mgc.to/sites//web/upload/files/mojimevadovepukabujefilaj.pdfIn PDF document text
    • http://collegium-connect.nl/ckupload/files/51685736465.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab2b2195940---ponifiwededajijox.pdfIn PDF document text
    • http://phantasos.org/userfiles/file/57875061993.pdfIn PDF document text
    • https://duocvinhkim.com/userfiles/file/zejafogapilefuxijidaje.pdfIn PDF document text
    • https://whitesal.com/data/images/file/1931_20210523025623.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160e982772532d---7240302043.pdfIn PDF document text
    • http://vssteel1999.com/ckeditor/userfiles/files/44973999042.pdfIn PDF document text
    • http://dienlanhtruongson.com/upload/files/22269090642.pdfIn PDF document text
    • https://aneri12.cz/res/file/devuzudodav.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/dfeae52d92a83b0e66b84af771849ffa/botufamevinaxisusotux.pdfIn PDF document text
    • http://nkcophs50threunion.com/clients/0/01/014062e559e26c1cf0711bcec4e573ae/File/17900819702.pdfIn PDF document text
    • http://3qlohas.com/CKEdit/upload/files/3268812882.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160fbe5f274d9d---fejapaxelipaji.pdfIn PDF document text
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/160837d891db8e---12482296534.pdfIn PDF document text
    • http://hhoasis.org/app/webroot/img/fck/file/luvutagakus.pdfIn PDF document text
    • http://www.guus.edu.mn/ckfinder/userfiles/files/tixosegasifefabife.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/16087449240c0c---77916138916.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_off0000d57f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD57F 11040 bytes
SHA-256: ee02a67ddf7c4f38c30f84990082d4acb5e14ebd9a6bf9801d946aa37ca0899d
font_01_sfnt_off0000ee9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE9D 17816 bytes
SHA-256: 6328a4276848b41ec9e18e563c7d394ab26956af6e0a48c420fbcdcd2647181a
font_02_sfnt_off00011b89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B89 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1