Malicious PDF — malware analysis report

Static analysis result for SHA-256 11bdf1139abb9841…

MALICIOUS

PDF

84.6 KB Created: 2021-10-05 22:08:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: aad4f8f2e31d35d49a739d1af313c20c SHA-1: 8b13e6d5f825ebf087e0df3a27bf8870fc7e60ef SHA-256: 11bdf1139abb984173517d2b0de62436960b9c493ec53732e870cf30d3a4c5eb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF contains numerous external links, many pointing to potentially disposable domains, suggesting a link farm or phishing lure. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards an attempt to redirect users to malicious content, likely as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://mkart.it/uploads/file/doraru.pdf In PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/45308547457.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/f77c44db141b032d1617c6a9c7c43531/zuriloripatudomo.pdfIn PDF document text
    • http://greatwalledmond.com/ckfinder/userfiles/files/junilugak.pdfIn PDF document text
    • http://myrbacken.se/login/ckfinder/userfiles/files/botopugig.pdfIn PDF document text
    • http://om-ar.com/userfiles/file/viboz.pdfIn PDF document text
    • http://sirindhorn.net/upload/File/48441581261.pdfIn PDF document text
    • https://vietnaminsight.biz/ckfinder/userfiles/files/71827206849.pdfIn PDF document text
    • http://hsi-international.com/ckfinder/userfiles/files/33755020597.pdfIn PDF document text
    • http://peak-experience-japan.com/images/blog/file/12409653959.pdfIn PDF document text
    • http://avandcie-energy.fr/ckfinder/userfiles/files/82187452513.pdfIn PDF document text
    • http://alhambra.kopanramen.com/uploads/files/16649339200.pdfIn PDF document text
    • https://sportuna.be/ckfinder/userfiles/files/77484261054.pdfIn PDF document text
    • https://congthuonghotel.vn/app/webroot/files/images/pages/files/93628656236.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/wugipiwisowu.pdfIn PDF document text
    • http://lnhaihui.com/userfiles/file/20210907071739_313502014.pdfIn PDF document text
    • https://meesens.be/KrMee/Tekstverwerker/46829185653.pdfIn PDF document text
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/vpkadjan7adspqlsjuv4ocb04o/34121305268.pdfIn PDF document text
    • http://mh-gartengestaltung.de/userfiles/file/lunemafimelafazifedebam.pdfIn PDF document text
    • http://technestudio.eu/userfiles/files/vedaguwigazurij.pdfIn PDF document text
    • http://yevres.fr/ckfinder/userfiles/files/46534735685.pdfIn PDF document text
    • http://semihkerpiccilervesupersound.com/upload/file/pexarinutej.pdfIn PDF document text
    • https://weekendtripskolkata.com/userfiles/file/foker.pdfIn PDF document text
    • http://artikos.pl/userfiles/file/38216181879.pdfIn PDF document text
    • https://fundacjanadzieja.com/images/wyswig_images/file/kajuji.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=homemade+chicken+nuggets+in+an+air+fryerPDF 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_off0000dfea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFEA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f7fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7FC 19632 bytes
SHA-256: 20a12ba082a14ceb4cea91efab58c3ca034b71056462b0571f73efd992b8cddc
font_02_sfnt_off00012b00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B00 11176 bytes
SHA-256: aa7381df12072e540ee047ec69b692ae006535af8a55fd3816c9e82bcfc785a9