Malicious PDF — malware analysis report

Static analysis result for SHA-256 936ec5e5a88346f1…

MALICIOUS

PDF

86.5 KB Created: 2021-09-21 02:10:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 86fbbcf733192b2dd46aba3b3a29cbf0 SHA-1: 2c00782ac28c3cf21b097644d5011d37d110672a SHA-256: 936ec5e5a88346f11141f68cdfa0e1511894390eb31773ab5a0a1a9cfe1181fd
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to other PDF files hosted on various domains, indicative of a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this malicious intent. While no scripts were explicitly extracted, the nature of the embedded URLs and the ML classifier's high confidence score point towards a phishing or SEO manipulation scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://griesvoegwerken.nl/UserFiles/file/21793164342.pdf In PDF document text
    • http://songpinhao.com/userfiles/files/dosimekel.pdfIn PDF document text
    • http://polyacer-ecp.com/userfiles/files/20210905_232002.pdfIn PDF document text
    • https://vanrun-it.nl/userfiles/files/bavibosuxowotakuz.pdfIn PDF document text
    • http://fazekaskozpont.hu/images/upload/file/57669102793.pdfIn PDF document text
    • http://iscelenie.info/files/file/3832572784.pdfIn PDF document text
    • http://saltokisport.com/uploads/files/gaxoxugataxemiso.pdfIn PDF document text
    • https://ozanetiket.com/TasarimAcarnet/serhali/upload/files/39298383802.pdfIn PDF document text
    • http://agppi99.pretty-match.com/upload/files/lajoroxurujibapuzobam.pdfIn PDF document text
    • https://karjerastests.bankai.lv/ckfinder/userfiles/files/80776643428.pdfIn PDF document text
    • http://health-bridge.in/upload/file/97622175913.pdfIn PDF document text
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614368b07479c---2561413400.pdfIn PDF document text
    • http://tofuyatogo.com/uploads/files/85538228909.pdfIn PDF document text
    • http://namuvaldymas.lt/userfiles/file/48307879.pdfIn PDF document text
    • http://www.ez4parcel.net/upfile/files/2021/09/07/8501284393.pdfIn PDF document text
    • https://dtd.com.pk/ckfinder/userfiles/files/82306279100.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161440e8813785---95762523657.pdfIn PDF document text
    • http://diamant-x.sk/UserFiles/file/86464495294.pdfIn PDF document text
    • https://razredna-nastava.net/files/80465349266.pdfIn PDF document text
    • http://linza-market.ru/upload/files/86237613006.pdfIn PDF document text
    • https://nk-sostanj.si/files/file/54946918983.pdfIn PDF document text
    • http://alumcity.ru/userfiles/file/xebalasa.pdfIn PDF document text
    • http://geoodwierty.pl/files/file/20455641583.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=best+video+editing+software+for+pc+crack+versionPDF 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_off0000ec35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC35 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010447.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10447 17908 bytes
SHA-256: f27d41c298eedb6bb28a2b8ab9d878255ef143de94535a57ad6467e7a0113844
font_02_sfnt_off00013271.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13271 11044 bytes
SHA-256: a80aa303bacbb4b8afe964f964b7d660783ca8cd9dad1ce0de0f393043041bf3