Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a4b8cd61a7b37bb…

MALICIOUS

PDF

83.3 KB Created: 2021-09-15 22:52:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 03723d1ca0c6fb04ededebee133d52b4 SHA-1: 0ce919ce9e7e6ffd871308198b4fab454fd7ddd3 SHA-256: 3a4b8cd61a7b37bbe00e643063d1254104ea8d2ba13a76225f133cc7b23abaca
96 Risk Score

Malware Insights

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

The ML classifier strongly indicates maliciousness, supported by heuristics identifying the PDF as a link farm pointing to compromised WordPress uploads and disposable domains. The document body is heavily obfuscated, but the URLs suggest a lure for downloading a game, likely to distribute malware. No scripts were extracted, limiting further analysis of specific payload delivery mechanisms.

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://crysiq.ru/uplcv?utm_term=download+game+digimon+world+3 PDF link annotation
    • http://xn----ctbguteehkho5h.xn--p1ai/ckfinder/userfiles/files/sorapofazabapesesakepabol.pdfIn PDF document text
    • http://abnicum.com/files/file/sosoro.pdfIn PDF document text
    • http://exosushi.com/uploads/files/judebosasusomoxe.pdfIn PDF document text
    • http://chiesamadremarsala.eu/userfiles/files/dixudufar.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161373f642e248---vefujixuvotabup.pdfIn PDF document text
    • https://ustunbilgisayar.com/userfiles/files/14933373385.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161331af797318---volenibikodazuwi.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/tftb8ieps9tue13l1hkkp9gp65/85188349768.pdfIn PDF document text
    • http://eis-pieschel.de/UserFiles/File/wokanolikekivipafidulipa.pdfIn PDF document text
    • http://tecnoservizi.com/userfiles/files/21871547434.pdfIn PDF document text
    • http://cukrarnakolbaba.eu/obrazky/files/vepewetexifobo.pdfIn PDF document text
    • https://daquin-ferriere.fr/userfiles/file/29034270713.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1613d9319aa8b3---21483879536.pdfIn PDF document text
    • https://mtydizayn.com/userfiles/file/xazawikoguper.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/97842420087.pdfIn PDF document text
    • https://cartolmania.it/file/82690162825.pdfIn PDF document text
    • http://physio-praxismitte.de/userfiles/zojuwe.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/19a9db2690447125a5fb89179e4919c9/142725085.pdfIn PDF document text
    • http://salamatekhanevadeh.ir/ckeditor/files/files/76670964162.pdfIn PDF document text
    • http://nataliashishkina.com/userfiles/file/nagitonejudoxedukedevalu.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/3rja6v7gehlklotphhuhdp45cc/nesireturavafimi.pdfIn PDF document text
    • http://pescepiana.eu/userfiles/files/tagemopibabolabokilepivu.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_off0000e13f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE13F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f956.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF956 10584 bytes
SHA-256: b65bbbd318648ef161959ad55970a5159ac1db0aaaccc5e0f68449c457e72d92
font_02_sfnt_off00011140.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11140 18008 bytes
SHA-256: d42aa91dfb3af94d88f259759cef702d98abeed3461c6003d9ab93c6095acf64