Malicious PDF — malware analysis report

Static analysis result for SHA-256 818d693380fa9d18…

MALICIOUS

PDF

80.8 KB Created: 2021-09-13 17:04:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 33b5414673d58782617e3b59d7d88998 SHA-1: c66d0e84a89007cf827ad1283339a732512b3d4e SHA-256: 818d693380fa9d186dabf4f254fe5d425b97eebfb699f01c621910811f4094e8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to unknown domains, and is flagged by ML classifiers and ClamAV as malicious. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a likely attempt to obscure malicious links or distribute content across many domains. While no scripts were explicitly extracted, the PDF structure and embedded links suggest it's designed to redirect users to potentially harmful content, aligning with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://bongkartuantakur.com/contents/files/wogawikopowe.pdf In PDF document text
    • http://vinaktv.com/storage/ckfinder/files/nevimedadeliz.pdfIn PDF document text
    • http://s4l.vn/storage/ckfinder/files/kilofize.pdfIn PDF document text
    • https://thanaclusterwestgate.leaddeehub.com/userfiles/files/55211890480.pdfIn PDF document text
    • http://agisma.ru/files/pages/files/vitunekofiretujegizezib.pdfIn PDF document text
    • https://vietnaminsight.biz/ckfinder/userfiles/files/vejamalow.pdfIn PDF document text
    • http://commissioncollectionlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/mejunadiditamotozizuxeza.pdfIn PDF document text
    • http://stadtbild-intervention.de/Quansis/ckfinder/userfiles/files/103431325.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/jirowodebolurexun.pdfIn PDF document text
    • http://pusancard.com/userData/board/file/24985159731.pdfIn PDF document text
    • http://hongdanhaudio.com/luutru/files/xabomamofawakevokog.pdfIn PDF document text
    • https://processwork.archerhuang.com/ConImg/files/xefujosetumewud.pdfIn PDF document text
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/d9k66bjv1575tsfihrsjqaetis/siseki.pdfIn PDF document text
    • http://kimwendelldesign.com/ckfinder/userfiles/files/17009577164.pdfIn PDF document text
    • http://hengtongrongshang.com/jingkelun/userfiles/files/20210912015218.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/16139357f07262---lanegenukojiti.pdfIn PDF document text
    • http://minipit.com/data/files/21727817834.pdfIn PDF document text
    • http://vietdubai.com/userfiles/file/werujub.pdfIn PDF document text
    • http://primeasset.hu/fileok/file/marukuserubafegax.pdfIn PDF document text
    • http://liburnia.pl/userfiles/file/xudeduzif.pdfIn PDF document text
    • http://riccaassociati.eu/userfiles/files/pidirunujamu.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1612f00c46c1df---bezijezofekikewoxudisen.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/xaretulusuzabova.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210910/file/16312281297787.pdfIn PDF document text
    • http://liga-stf.ru/i/upload/files/kewalom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=list+of+world+problems+2020PDF 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_off0000d8c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8C8 16984 bytes
SHA-256: e279e24720a5de42aa3fe7f50e9a13d8219383b92c30154859fb71c664c6306e
font_01_sfnt_off00010425.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10425 10820 bytes
SHA-256: 0c8cfa8ddc6c1ad900a37ce047f8859fb1c092f5aad1cbfe8f2552ce298f9aae
font_02_sfnt_off00011cfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1