Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b711796d0724c0a…

MALICIOUS

PDF

81.5 KB Created: 2021-09-11 22:52:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 03b13ffb47f737cd9adf6da3962c0ad1 SHA-1: 7828467a129caefff220f7ad23b08df39c242136 SHA-256: 4b711796d0724c0a9b621367e9d6435189030af8f499e892c261b13e08c6435e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, with heuristics indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. The presence of multiple external links points towards an attempt to redirect the user to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://cyberbirddog.com/userfiles/files/85310433050.pdf In PDF document text
    • http://doo-san.com/userfiles/file/20210906190731.pdfIn PDF document text
    • http://tcgardening.com/userfiles/file/2021091115062873499.pdfIn PDF document text
    • http://stefani.cz/fck/file/beguwafegin.pdfIn PDF document text
    • https://immsac.pe/sgi_userfiles/userfiles/files/kamuzinulesefali.pdfIn PDF document text
    • https://upbfassadenbau.com/upload/file/tononumibujizu.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/161325f4f082b7---kokuminotumakanifowolu.pdfIn PDF document text
    • http://maulich.vn/attachment/files/vomedebisupumadufuxikini.pdfIn PDF document text
    • http://drapikowski.pl/uploaded/fck_files/file/18552802808.pdfIn PDF document text
    • http://dkkarsin.pl/img/upload/files/3917899874.pdfIn PDF document text
    • https://nationalshield-uae.com/userfiles/files/kibole.pdfIn PDF document text
    • http://vinhthuan.vn/upload/files/domebines.pdfIn PDF document text
    • https://minjar.mebel18.com/uploads/files/samogegumumikukizuxosuk.pdfIn PDF document text
    • https://segurodegranizo.ar/noticias/fckeditor/file/16762567627.pdfIn PDF document text
    • https://underworldgear.com/admin/images/fckImg/file/mupogonezelaxireli.pdfIn PDF document text
    • http://bitite.lv/media/txt/122/file/wujofezipapowoxapaja.pdfIn PDF document text
    • http://henanshuangxin.com/d/files/61926080535.pdfIn PDF document text
    • https://sieuthimaytinhcu.vn/upload/files/97275925870.pdfIn PDF document text
    • http://elpijisystem.com/file/48145239574.pdfIn PDF document text
    • https://cmoretv.com/userfiles/sewoso.pdfIn PDF document text
    • http://jezirka-biobazeny.cz/UserFiles/File/11682223989.pdfIn PDF document text
    • https://innotek.vn/uploads/news_file/beganu.pdfIn PDF document text
    • http://ammk.sk/userfiles/file/jixepebiloluwoxig.pdfIn PDF document text
    • https://www.greenlakecruises.com/ckfinder/userfiles/files/29784384609.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=kwai+hacker+apkPDF 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_off0000d564.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD564 10104 bytes
SHA-256: f224e8aaf99e2a8374faefdd954de9e1f7149b14670ed7094907cab7542c3035
font_01_sfnt_off0000ec1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC1A 19776 bytes
SHA-256: 662405b6de6ae71935faba05bec680fef4c837ad5c7df5b7a5df85a5c10d79a6
font_02_sfnt_off000120f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1