Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6f9d55b28698458…

MALICIOUS

PDF

86.1 KB Created: 2021-08-12 18:27:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 121c5610da2b3ddd3aa1d38cefe78117 SHA-1: b471f4d78528b015cbd063db269bea9fa39f161a SHA-256: c6f9d55b286984587d1b0b5e4f4ebdce4b1f3592553832be2b7050e06620a234
96 Risk Score

Malware Insights

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

The PDF file contains a link farm, with many URLs pointing to compromised CMS upload directories, suggesting an attempt to lure users to malicious content. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm the presence of numerous external links, some on disposable hosting, characteristic of SEO poisoning or phishing attempts.

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 http://litho-and-co.fr/ckeditor/upload/files/pafajiwimufanenititivuro.pdf In PDF document text
    • http://synerfreight.com/syner_upload/images/files/2968442353.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/67898650264.pdfIn PDF document text
    • https://bio-obst-und-gemuese.de/userfiles/file/wodizekobinitugawumesaxe.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078be28bb54d---daxejovebuw.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160735f7d0c311---lekawudodamus.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/p9gtc45t555u5mkk1mfbb3f486/35021052703.pdfIn PDF document text
    • http://fskyok.com//uploadfile/files/85889084573.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607f836322d14---1305372897.pdfIn PDF document text
    • https://dp-silver.com/userfiles/file/liwavosakifelasulila.pdfIn PDF document text
    • http://gesundimjob.at/images/content/files/minelo.pdfIn PDF document text
    • http://qytbearing.com/upfile/file/lavefajizexoxuwekawafumux.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/16077d57bbcb98---delemeferitulolix.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd584e0acdf---jakozedoko.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/dmoo2dl26bciaf1v5m84pp7s42/lubodulakinamexapamuwuno.pdfIn PDF document text
    • http://hesexpo.com/img/editor/image/file/24855416431.pdfIn PDF document text
    • http://vinmexindia.com/uploads/tebujekenigozejenewat.pdfIn PDF document text
    • http://adria-ex.com/images/blog//file/nebes.pdfIn PDF document text
    • http://diakmelo.hu/ckfinder/userfiles/files/tozetenegawubitujezij.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/7c59375aae9feaf12c2b17446fe3b91d/78121401375.pdfIn PDF document text
    • http://netflor.pl/upload/File/66933604634.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160857df985935---baparabodiko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+check+grammar+appPDF 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_off0000edfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDFE 10580 bytes
SHA-256: 2c49ff68f00fd71ce3801293bcf53f301c9d77a9338eb84968e461068b150d79
font_01_sfnt_off00010635.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10635 16860 bytes
SHA-256: 84297a8f50f2026544b9d5f3a1f61b8bee5e0c84b82d51b50f0cfdb10119871a
font_02_sfnt_off0001320b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1320B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1