Malicious PDF — malware analysis report

Static analysis result for SHA-256 835d534d2214c312…

MALICIOUS

PDF

68.9 KB Created: 2021-09-26 18:47:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b8dff7934dcf8f5325c6c7f7390019be SHA-1: 87c1db9d6fa08018b28949b78b7eb3ed6884854e SHA-256: 835d534d2214c312fedfc2eacb53586da3d286ed7d7b99c633b84cb0d93aed32
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs pointing to various domains, suggesting a link farm or phishing lure. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics strongly suggest an intent to redirect users to malicious sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://philabc.ru/uplcv?utm_term=live+wallpapers+free+download+for+android+tablet PDF link annotation
    • http://thestarbusan.com/FileData/ckfinder/files/20210907_23C32F55CA9F7B35.pdfIn PDF document text
    • http://nakloboucku.cz/uploaded/file/resus.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/nbvb3v5r6g516aufvlbk4cate3/kumajitisiro.pdfIn PDF document text
    • https://tradingphrases.net/userfiles/files/wikumupugujose.pdfIn PDF document text
    • https://kemxoithanhhang.vn/app/webroot/files/images/pages/files/37506525812.pdfIn PDF document text
    • http://transgusto.ch/userfiles/file/77611642261.pdfIn PDF document text
    • http://divapharma.com/uploaded/file/77691955370.pdfIn PDF document text
    • http://stepasidemedical.com/images/uploads/file/famozusorazakegazelawu.pdfIn PDF document text
    • http://s4l.vn/storage/ckfinder/files/76475290760.pdfIn PDF document text
    • https://cape-electronics.com/media/file/dorinawe.pdfIn PDF document text
    • http://turinhotelcompany.com/userfiles/files/64691998602.pdfIn PDF document text
    • https://alrukn.co/userfiles/files/bonub.pdfIn PDF document text
    • https://pernambucoimortal.com/imagens/files/58671246711.pdfIn PDF document text
    • http://iraneto.com/basefile/iranetocom/files/58195650831.pdfIn PDF document text
    • http://joyearland.com/ckfinder/userfiles/files/wixokejazisimusedis.pdfIn PDF document text
    • https://shih-tzu.ro/files/file/14772202173.pdfIn PDF document text
    • http://njuhome.pl/ckfinder/userfiles/files/55567428039.pdfIn PDF document text
    • http://chongthamnguoc.vn/img/files/84440663070.pdfIn PDF document text
    • https://wroclawmodelshow.pl/ckfinder/userfiles/files/josimo.pdfIn PDF document text
    • http://888chji.com/userfiles/files/98658754512.pdfIn PDF document text
    • http://medicareclinichowrah.net/faboriginelist-braj/userfiles/file/sonosaf.pdfIn PDF document text
    • http://self119.net/upload/userfiles/2021/09/files/210917120724.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/88170793374.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/luwukum.pdfIn PDF document text
    • https://tavfelugyelet.megujuloenergiapark.hu/admin/ckfinder/userfiles/files/51106947030.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_off0000ae6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE6F 14840 bytes
SHA-256: 7dfc4e7a60724116dacf0b47154d1b3ac97958965b8acb7f384b517745c43027
font_01_sfnt_off0000d346.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD346 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eb5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB5D 10740 bytes
SHA-256: 9cc0c073b7f2cc60f28d335284237c93ed30d62e266d3aebb748f9a478b72664