Malicious PDF — malware analysis report

Static analysis result for SHA-256 25a5c0e3d4db40dc…

MALICIOUS

PDF

79.7 KB Created: 2021-09-13 13:17:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 776aab7a96c222f16ef5afdfb2b777be SHA-1: b821f90f8c625a2342f39a7fd374d050cd4e6a7b SHA-256: 25a5c0e3d4db40dc7b7d4c1a919b704036583d5789a56141ea15b3ffa3601ea5
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to other PDF files hosted on various domains, suggesting a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics reveal.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://itcbeautytrainingschool.com/userfiles/file/7923989429.pdf In PDF document text
    • http://danangsculpture.com/uploads/image/files/23406769684.pdfIn PDF document text
    • http://citysoupsbellevue.com/uploads/files/89750851167.pdfIn PDF document text
    • http://iwort.de/userfiles/file/nesuguf.pdfIn PDF document text
    • http://glampingcaravan.com/userfiles/file/20210913080735.pdfIn PDF document text
    • http://kingtonkatsu.com/uploads/files/90041318247.pdfIn PDF document text
    • https://5a.ro/ckfinder/userfiles/files/19975242441.pdfIn PDF document text
    • http://thienminhgroup.com/uploads/userfiles/file/70155196682.pdfIn PDF document text
    • https://cursosadistanciayonline.com/medios/files/gozoravigalumime.pdfIn PDF document text
    • http://kondicionery-domodedovo.ru/upload_picture/file/24258639568.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/0c8a4e60879acd91d8b12d0b423aaef5/miwurisuzamutigemiwoloxu.pdfIn PDF document text
    • http://progetec.org/userfiles/files/virisifufotuzulibilajudog.pdfIn PDF document text
    • https://fairtradeportal.pl/userfiles/file/56143901775.pdfIn PDF document text
    • https://inprovitchile.com/ckfinder/userfiles/files/sinasojelimizob.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613964b2c0d29---wajakiliwigufapixum.pdfIn PDF document text
    • https://www.wappa.com.au/siteadmin/ckfinder/userfiles/files/75271416595.pdfIn PDF document text
    • https://amzentransportationindustries.com/admin/imagetemp1/file/35411677241.pdfIn PDF document text
    • https://purefeeling8.com/data/file/fapevodizuxoderizodowoz.pdfIn PDF document text
    • http://tavio.su/files/file/lalugititufenidip.pdfIn PDF document text
    • http://ministerium.pt/files/32468629944.pdfIn PDF document text
    • http://sloplast.com/userfiles/files/jezenakapewemus.pdfIn PDF document text
    • http://teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/55589618542.pdfIn PDF document text
    • http://koszyczarek.pl/userfiles/file/bewijuvupemak.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=custom+rom+j110hPDF 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_off0000d392.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD392 17852 bytes
SHA-256: 6c61bb6e371b718c7cc71fe40e0d298cb35769ba6ab390b68220d71afcec983a
font_01_sfnt_off00010276.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10276 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A8D 10272 bytes
SHA-256: a3dfa0ff4451c509165ec666b8e58228b2e87fd5be0b69c5fb81d0a6ccd28c9a