Malicious PDF — malware analysis report

Static analysis result for SHA-256 4244bef9cb45541e…

MALICIOUS

PDF

81.7 KB Created: 2021-06-27 11:53:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 611d75ee8f93b9043e5be099ba998d46 SHA-1: 87e105fada128ad2a774151ab67ad1933b4c0f69 SHA-256: 4244bef9cb45541e84bc004049963c66d90e6c428875d6e842e03ab16144438c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, but the structure and URL patterns are indicative of a phishing or malware delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9933

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://krisoc.ru/uplcv?utm_term=discriminant+calculator+with+solution
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/918u64hje9tbdpirs5hh3ihrj0/ripuvululalime.pdf
    • http://parbatsamajjapan.com/img/files/files/sunol.pdf
    • http://lawngo.net/fckfiles/67246900128.pdf
    • https://ecoretras.com/file/tesoxevufuwinebom.pdf
    • http://salinahighschool1968.com/clients/3/33/33fcb9b832a528c934b1ac42c6b88a99/File/sosaz.pdf
    • https://www.straightmyteeth.eu/wp-content/plugins/super-forms/uploads/php/files/fe64e02eca9dac5cd8b4db8e27a52005/fexemepukidujazukatofubo.pdf
    • https://nolimitscenter.be/peausitive/images/FCKeditor/file/89097770430.pdf
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/420446575f3f19025e775801e30c8ced/62919156155.pdf
    • http://hjtech.org/admin/upfile/file/bewuximilojezosekoginul.pdf
    • https://ltgtrends.com/wp-content/plugins/super-forms/uploads/php/files/cb1bf8556ed6acd824827423b6b6fdee/rawesokuwujetozenoguditap.pdf
    • https://vegan-eshop.cz/data/file/12304048506.pdf
    • https://nic-irq.com/userfiles/files/52462942642.pdf
    • http://piotrkowska77.pl/zdjeciafile/79583947516.pdf
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b86676b638f---29114293897.pdf
    • http://bilmatbasim.com/userfiles/file/90174894233.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160750b6187672---nigilixapivoraso.pdf
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/b1eb2f50a0114f268b4484a83f241afb/xerupijarogokuwutelonat.pdf
    • http://zhengfutz.com/v15/Upload/file/20215132252579072.pdf
    • https://aspaeng.com/files/image/files/94661072794.pdf
    • http://win-sonic.com/kida2018/ck_imgs/files/20158873197.pdf
    • https://nadinerogger.ch/userfiles/files/6063142947.pdf
    • http://hpworld.hu/data/pic/Image/file/botuwaxuzifozitozaluvazon.pdf
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b43ba9768a8---fanofas.pdf
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/1460138p85kcis6dauko720320/49267232435.pdf
    • http://clarklawtexas.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/muvinuvexogiron.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c0eb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC0EB 16792 bytes
font_01_sfnt_off0000d8fc.bin
45759b2213af7bd255fdba92d62843a76ad2db5d0a0ba514554a9ca6b8faa514
pdf-font-stream PDF embedded font (sfnt) at offset 0xD8FC 17820 bytes
font_02_sfnt_off0000f3f8.bin
71e4962b4f6f51f63d03c49e0aa75cbb5b96d4a7b465d6d108e40d4f3f7de7af
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F8 10552 bytes
font_03_sfnt_off00010bdf.bin
6bdc6c5259a87631dfc340f4ddee5a7f25cef69e61ab9ab8e04123e4fbb73dd1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BDF 17164 bytes