Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b9802fc00c479ff…

MALICIOUS

PDF

71.4 KB Created: 2021-09-09 10:34:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 21a5a7ad47100babe30fec4ea0dfeacc SHA-1: 2add80c2ae6114d3901d8ac03c679e2f42cd493e SHA-256: 6b9802fc00c479ff1ee3842c1ce9308220f40cbee25154a6d3bada1602260170
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to external resources, many of which are hosted on disposable domains and appear to be part of a link farm. The heuristic 'PDF_RANDOM_URL_LINK' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicate a malicious intent to redirect users to potentially harmful content. The ML classifier and ClamAV detection further support the malicious nature of this file, suggesting it's a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://peter-scherer.de/userfiles/file/14816529852.pdf In PDF document text
    • https://ehbo-oostkapelle.nl/userfiles/file/bamufolisiju.pdfIn PDF document text
    • http://ambulatorioveterinariobubiniregini.eu/userfiles/files/32311348471.pdfIn PDF document text
    • http://yizhu580.com/ckfinder/userfiles/files/45141532577.pdfIn PDF document text
    • http://sushistoryus.com/uploads/files/fodevoxotinajako.pdfIn PDF document text
    • http://leicesterbiketec.com/userfiles/file/26167889018.pdfIn PDF document text
    • https://menu2uplus.com/images/file/rakukumexevubawad.pdfIn PDF document text
    • https://eletmodguru.hu/files/files/nisumunutidibuwojo.pdfIn PDF document text
    • http://brilliantsolarpaneling.com/userfiles/file/53101364238.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/97c6d3776d5777527c6dd63f0c274db9/pakamozu.pdfIn PDF document text
    • http://totoumi.jp/upload/file/29486185447.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137d07ba5af8---17852840491.pdfIn PDF document text
    • http://apsons.eu/files/file/21067682872.pdfIn PDF document text
    • https://kitapkaplama.com/upload/ckfinder/files/zurotodogasigabebox.pdfIn PDF document text
    • http://dansecyr.ca/pdf/file/8452248912.pdfIn PDF document text
    • http://radtel-sport.pl/userfiles/file/domiwuw.pdfIn PDF document text
    • http://ascensionchina.com/userfiles/file/95726947833.pdfIn PDF document text
    • http://mfahk.com/upload/files/63012281175.pdfIn PDF document text
    • https://nguyenhungstone.com/uploads/image/files/kukugakadogepanukiputoja.pdfIn PDF document text
    • https://khoahoc.timviec365.com/picturesfiles/49685903768.pdfIn PDF document text
    • http://bon-mar.com/fck_user_files/file/lakup.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/mamofawow.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=download+game+psp+romsmaniaPDF 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_off0000b657.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB657 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE69 16068 bytes
SHA-256: 6c8f9a462e56defdf159d18c9d757bf29caa3aac104539040325135dbe84aac4
font_02_sfnt_off0000f7c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7C0 10724 bytes
SHA-256: e3eab2ec0f06e0da5283b9acca99eef33260f4c74922ddb600d1245298a8b38c