Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4d5861b0b419775…

MALICIOUS

PDF

69.2 KB Created: 2021-09-30 19:43:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 73584deb0d0869be4b22dd56c1daf1b3 SHA-1: a722ba74e6960ed6d28e8687d275dcd502015a78 SHA-256: b4d5861b0b419775e35d50eac093c254dc879db936e3157bb25f458c3fbc72e5
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, with one heuristic specifically identifying it as a link farm on disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and extensive URL usage suggest it's designed to redirect users to malicious sites.

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://krisoc.ru/uplcv?utm_term=free+download+ps1+emulator+for+android PDF link annotation
    • http://colleges-in-tamilnadu.com/FCKeditor/userfiles/file/wituvajikiso.pdfIn PDF document text
    • https://truckforceone.eu/upload/editor/file/41118783394.pdfIn PDF document text
    • http://www.oneworldkarate.com/fckeditorimages/userfiles/file/vitogemaxozatoxutamevo.pdfIn PDF document text
    • https://hbfilm.ca/resimler/files/52998322447.pdfIn PDF document text
    • http://ziva-muzika.cz/files/file/11084793301.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/34811441247.pdfIn PDF document text
    • https://tucarrorentacar.co/ckfinder/userfiles/files/23542791901.pdfIn PDF document text
    • http://aquarium-kochi.com/app/webroot/ckfinder/userfiles/files/ropemowijotozavedumomu.pdfIn PDF document text
    • http://sieuthimaynhapkhau.com/upload/files/savedenodoxejudupub.pdfIn PDF document text
    • https://www.tcf.gov.tr/ckfinder/userfiles/files/34965937097.pdfIn PDF document text
    • https://quizai.com/uploads/files/15062905802.pdfIn PDF document text
    • http://www.evisiontiendaonline.com/ckfinder/userfiles/files/guridoxivipoxoruregupu.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/1612f298284ec1---89411728477.pdfIn PDF document text
    • https://creativenursery.net/home/creative/public_html/ckfinder/userfiles/files/88809552146.pdfIn PDF document text
    • http://8njl.com/userfiles/files/70106189140.pdfIn PDF document text
    • http://konstruktor33.ru/app/webroot/files/files/7964194212.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/3757102547.pdfIn PDF document text
    • http://tomekorea.com/userData/board/file/rubugide.pdfIn PDF document text
    • http://custom-mugs-factory.com/uploadfile/files/25501151798.pdfIn PDF document text
    • http://ceramvetro.net/userfiles/file/86315576332.pdfIn PDF document text
    • https://laser123.com/geektic/files/62463406122.pdfIn PDF document text
    • https://aquatrustfina.com/userfiles/file/10788294029.pdfIn PDF document text
    • https://jcmimoveis.com/userfiles/file/15107745854.pdfIn PDF document text
    • http://bettaletroom.com/file_media/file_image/file/bovabilakonug.pdfIn PDF document text
    • 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_off0000af37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF37 10872 bytes
SHA-256: d53445a16be296521fb6238eb51260cddeea5610a59cd0aa2f487ad98f7715af
font_01_sfnt_off0000c866.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC866 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e078.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE078 15296 bytes
SHA-256: f769fdd4b2c969ca2169fb7ff75885072a794c6110ce740b353d79ac911a0902