Malicious PDF — malware analysis report

Static analysis result for SHA-256 91315e5005579fe1…

MALICIOUS

PDF

70.8 KB Created: 2021-09-10 04:02:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 84040c0136a1940aff1f23fb48ddd70b SHA-1: fd0a53a6243ec4ae949cdb7ab88c2aec9905e640 SHA-256: 91315e5005579fe1de1db02455dcd647c80e159ad435ba6d00c0b6599f58e9e1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates the document contains numerous links to disposable hosting sites, suggesting a link farm designed to obscure the ultimate destination. The embedded URLs, while many are marked benign, point towards a strategy of redirecting users to various external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://first-group.kr/ckupload/files/60944521374.pdf In PDF document text
    • http://www.ruben.pl/ckfinder/userfiles/files/11434202603.pdfIn PDF document text
    • http://naturestuff.nl/siteimages/file/64299744531.pdfIn PDF document text
    • http://3wsystems.com/shipinc/userfiles/files/5075684681.pdfIn PDF document text
    • http://www.lbtfilm.com/uploads/files/tikogikawuxoxorip.pdfIn PDF document text
    • http://crocepadrekolbe.it/userfiles/files/vojavomo.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fd39745503---dadodewemupotolul.pdfIn PDF document text
    • https://rainbowfurnitures.com/files/files/xovaza.pdfIn PDF document text
    • http://orenprom.com/img/account/file/zitazubakuxure.pdfIn PDF document text
    • http://casavacanzesanvito.eu/userfiles/files/narete.pdfIn PDF document text
    • http://www.pavimentosyreformasferlu.es/ckfinder/userfiles/files/lifituduruzuvil.pdfIn PDF document text
    • http://horizonpestservices.com/userfile/31396734340.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/gvctvm28p9e7l53pilup8778ir/69190866988.pdfIn PDF document text
    • https://hoongnau.com/upload/files/86605661388.pdfIn PDF document text
    • http://rybarict.cz/webpagebuilder/ckfinder/userfiles/files/17314477445.pdfIn PDF document text
    • https://svltv.in/userfiles/files/kovelufalujovezibesuzisev.pdfIn PDF document text
    • http://forepic.com/_UploadFile/Images/file/vunevar.pdfIn PDF document text
    • http://formpart.com/upload/ckfinder/files/51410078936.pdfIn PDF document text
    • https://villanakarin.com/userfiles/files/rovanurajele.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/rebuloguzodegoxubokemim.pdfIn PDF document text
    • http://thunderstar.cn/userfiles/file/20210903154836996212511.pdfIn PDF document text
    • https://www.potravinyav21.cz/ckfinder/userfiles/files/pevadubosinelojaruk.pdfIn PDF document text
    • http://parfumland.sk/upl/bajizajakajurolo.pdfIn PDF document text
    • https://arhstroi.by/uploads/files/71120050384.pdfIn PDF document text
    • http://bobiniauto.com/userfiles/file/xaripavo.pdfIn PDF document text
    • https://kimcert.com/E/file/limemasi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=professional+c%2B%2B+pdfPDF 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_off0000b6ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF01 10516 bytes
SHA-256: 78362095c6aa860037e0e6ddec051924bc47963c99bb23197ba60f3e1080f777
font_02_sfnt_off0000e701.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE701 15200 bytes
SHA-256: 48fa35d9f883b3771af869b849a02ea6df33d56ee455841afbbfbd5aeac14ccd