Malicious PDF — malware analysis report

Static analysis result for SHA-256 c21c6c68d061688f…

MALICIOUS

PDF

82.5 KB Created: 2021-09-22 22:32:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 821628b7ba64340656db9727c3eaa629 SHA-1: 0f1fd75a8054dc83b081775fba1e27615d2711c9 SHA-256: c21c6c68d061688f28d4373c040759e8b6e9860fc6aaab1c17b62040a258f2a1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple disposable domains, which is a common tactic for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and the presence of numerous external URIs suggest an attempt to redirect the user to a malicious site, likely initiated via a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/9e9b7ea4f7a9409ee2ca628a383ba27f/titemekavo.pdf In PDF document text
    • http://gongotour.com/FileData/ckfinder/files/20210920_73C179C42DE163FB.pdfIn PDF document text
    • https://cosmeticdermatologymiamibeach.com/uploads/data/files/41487539102.pdfIn PDF document text
    • https://cribpointonline.org/cribpointonline/userimages/file/wesiki.pdfIn PDF document text
    • http://herningbadintra.dk/app/webroot/upload/files/27247316183.pdfIn PDF document text
    • http://chukgoobok.com/files/fckeditor/file/sofikelevolexigifavujug.pdfIn PDF document text
    • https://taxforce.nl/userfiles/files/50791417923.pdfIn PDF document text
    • http://vanprodukt.cz/UserFiles/File/tixumopux.pdfIn PDF document text
    • http://ty-int.com/files/files/nabojojop.pdfIn PDF document text
    • https://wigs4less.net/nbloom/fckuploads/file/lunajabujeletepu.pdfIn PDF document text
    • http://harc-ias.vn/Images_upload/files/91047731697.pdfIn PDF document text
    • http://beiwendq.com/userfiles/file/81993019815.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/mopivozuvumakaxanizunari.pdfIn PDF document text
    • http://khamtribacninh.com/images/files/tidezarujikin.pdfIn PDF document text
    • http://cosmikkino.ru/sadm_files/93392130501.pdfIn PDF document text
    • http://haisushitogo.com/uploads/files/72636958729.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/pisivukirobitolonow.pdfIn PDF document text
    • http://suliaok.com/v15/Upload/file/2021921107255616.pdfIn PDF document text
    • http://sevoir.hu/uploads/file/27133331471.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/16141cb84a6003---95603017572.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/file/gosuk.pdfIn PDF document text
    • http://www.vlaamspatientenplatform.be/_plugin/ckfinder/userfiles/files/95634676348.pdfIn PDF document text
    • http://tobn56.com/UpFiles/file/lomodisugibibewadaju.pdfIn PDF document text
    • http://hyosangjo.com/userfiles/file/20210903095730.pdfIn PDF document text
    • https://transmilenio.net/datamont/userfiles/file/3628253833.pdfIn PDF document text
    • http://fishtech.org/uploads/userfiles/file/file/49683787197.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=adjectives+that+start+with+o+to+describe+a+personPDF 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_off0000dce3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCE3 17676 bytes
SHA-256: 72363dadc37a4a55b6e76a133a660d9879d20ed2d7aced65350b8df07ac4b47c
font_01_sfnt_off00010a86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A86 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001229d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1229D 10968 bytes
SHA-256: b0d5a16fcb3832f78b76450b3ebce6d50bb111fdfcef4a6a74fb9079b21bbab9