Malicious PDF — malware analysis report

Static analysis result for SHA-256 299bf06146bc859e…

MALICIOUS

PDF

69.8 KB Created: 2021-09-16 00:49:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 8d101103c5f6293f5885d3e785c10bc4 SHA-1: 47431a5b391828bbae53d5ff0e45511320b2b790 SHA-256: 299bf06146bc859e04dd3658b2cf8afa7420cb3e8a55ffe445c29a4fb117fbc7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to external PDF files, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF is designed to host many links on disposable domains. While no scripts were explicitly extracted, the nature of the embedded URLs and the overall structure suggest it's likely used as a lure for phishing or to distribute further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://donghobaoan.com/uploads/files/wemapitinivozakegok.pdf In PDF document text
    • https://semot.com/Store/userfiles/file/taputato.pdfIn PDF document text
    • http://www.heksan.com.pl/file/51170467231.pdfIn PDF document text
    • http://www.primariasantana.ro/uploads/file/39402296433.pdfIn PDF document text
    • http://arkystudio.eu/userfiles/files/63337134922.pdfIn PDF document text
    • http://www.hgbehringer.de/img/files/files/51202372658.pdfIn PDF document text
    • http://hitechdentalhouston.com/uploads/files/70587259089.pdfIn PDF document text
    • http://rayocazar.com/images/elfinder-1.1/files/file/negogixivawupu.pdfIn PDF document text
    • http://alarcon-v.com/editor_upload_image/file/miwobo.pdfIn PDF document text
    • https://themalc.org/files/file/pitibanofal.pdfIn PDF document text
    • http://architettotoma.it/userfiles/files/57558638532.pdfIn PDF document text
    • https://butyfarm.mm520.net/userfiles/files/50374134097.pdfIn PDF document text
    • http://www.jucadent.es/ckfinder/userfiles/files/13954251683.pdfIn PDF document text
    • https://mmtours.si/uploads/56436517959.pdfIn PDF document text
    • http://domosplast.hu/files/file/17393797803.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/c65529b9a096ac8e1c74595f33f7f3e7/dikojesupivaziziwebinun.pdfIn PDF document text
    • http://telecycling.org/files/file/befopopu.pdfIn PDF document text
    • http://www.ecvbrass.ch/user/web/file/fiwajadunepivafegunu.pdfIn PDF document text
    • http://phongkhamthienhoa.vn/images/files/lugemovowaximuvadav.pdfIn PDF document text
    • http://www.s4b.nl/upload/files/leseri.pdfIn PDF document text
    • http://primeasset.hu/fileok/file/84251633413.pdfIn PDF document text
    • http://kzlo.pl/fotki/fotki/file/nupabinadokigaxowas.pdfIn PDF document text
    • http://rorolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pekusanusovukej.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=how+to+get+more+emojis+for+androidPDF 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_off0000b44d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB44D 10856 bytes
SHA-256: 9d27df1598d431633516d31f0b1462472db4a5e965f437b0c91d558841688cc4
font_01_sfnt_off0000cd23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD23 14432 bytes
SHA-256: 4edf129e26628798f3f59da471622ed3f07d2acfb66a712b6ffd353f45cb8662
font_02_sfnt_off0000f140.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF140 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1