Malicious PDF — malware analysis report

Static analysis result for SHA-256 c16b4577f181cc1b…

MALICIOUS

PDF

69.9 KB Created: 2021-09-25 01:06:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 670e28986d0a74e5684f9cc8025278ee SHA-1: d7bfb196c16e06ad20c63b1d917b778b28d95df0 SHA-256: c16b4577f181cc1b75cd61472802b2686508e5d6030db09febeb52bdbb728ea8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, with many pointing to disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point to a malicious document designed to exploit users by directing them to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://khogiaydantuonghanquoc.com/images/news/file/pozebijexexezogix.pdf In PDF document text
    • http://ulleungroadtour.com/FileData/ckfinder/files/20210921_25BF3068DD49BF0B.pdfIn PDF document text
    • http://billagelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/30976839768.pdfIn PDF document text
    • http://ngor2-3.com/file_media/file_image/file/sivur.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/07cb8e7a8a2625eb78d408973e976211/45298428579.pdfIn PDF document text
    • http://thaoduocvn.com/userfiles/image/file/xadagitajakakutim.pdfIn PDF document text
    • http://sparkpro.lv/content/file/lipazirazodajavofazewasa.pdfIn PDF document text
    • http://banglenhospital.com/UserFiles/File/lolosuzekatarixi.pdfIn PDF document text
    • http://moutierrozeille.fr/userfiles/file/99943699107.pdfIn PDF document text
    • https://festivaldelmaridaje.com/sgi_userfiles/userfiles/files/55786146058.pdfIn PDF document text
    • http://hillsdalehorseboarding.com/ckfinder/userfiles/files/13859676183.pdfIn PDF document text
    • https://karaari.leaddeehub.com/userfiles/files/15987640573.pdfIn PDF document text
    • http://gbfrjournal.org/pds/userfiles/files/midagerula.pdfIn PDF document text
    • http://harckocsik.hu/userfiles/file/kebujedakatibokupikafuf.pdfIn PDF document text
    • https://nada70.org/userfiles/file/71520752606.pdfIn PDF document text
    • https://doctmcooper.com/userfiles/files/8037608091.pdfIn PDF document text
    • https://pannonfinanz.eu/editor_up/rikenon.pdfIn PDF document text
    • http://studiogalata.it/userfiles/files/38579195541.pdfIn PDF document text
    • https://fluffy-chins.com/images/file/96437793220.pdfIn PDF document text
    • http://bnblspecialities.com/userfiles/files/77010866810.pdfIn PDF document text
    • http://nissanotogovap.com/uploads/images/files/relubugab.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132f5cc0b6e7.pdfIn PDF document text
    • https://equinox-e.com/upload/UserFiles/file/25192906838.pdfIn PDF document text
    • https://artgalery.ro/files/file/zavopuzelabidexegubi.pdfIn PDF document text
    • http://damnoen.com/ckfinder/pho/files/zazumibejafugisajusiji.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=office+365+outgoing+smtp+server+settingsPDF 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_off0000b21d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB21D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA2F 14848 bytes
SHA-256: 2d5bb94e3fd81e7d11a2a7b2f2bbcc7e6065b2578982e980875e863dcec78a24
font_02_sfnt_off0000ef44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF44 11280 bytes
SHA-256: 9be476e627195e4a6a5341219d3f3b7552a55d184738a899a13caed992f3630e