Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ef6d14befc2495c…

MALICIOUS

PDF

70.8 KB Created: 2021-10-01 06:56:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 660471143dd8adabf6876ed66f2d5442 SHA-1: 10c3c2dd8797b7084e8679e51b46357bd45d19b9 SHA-256: 6ef6d14befc2495c25a13d5050d49e90634f6af7307f2dea2849bbb8fd3955d8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to suspicious domains, suggesting it acts as a lure to a link farm or phishing site. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF is designed to redirect users to various disposable hosts. While no scripts were explicitly extracted, the nature of the PDF and its numerous links strongly suggest it is used for initial access, likely via spearphishing, to deliver further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://quangtriasianwindow.com/uploads/image/files/kiwudazabawudavak.pdf In PDF document text
    • http://zzquansu.cn/d/files/zekekolap.pdfIn PDF document text
    • https://x-software.cz/data/file/kamotasuku.pdfIn PDF document text
    • http://hyundai-baoloc.com/luutru/files/bikudilubomodabezokonafa.pdfIn PDF document text
    • http://betonkeritesek.eu/Content/files/28772137288.pdfIn PDF document text
    • https://euronet.stonavka.cz/webpagebuilder/ckfinder/userfiles/files/xigulosimivopewos.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-10/20210910022755713753.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/69613007492.pdfIn PDF document text
    • http://citra.cl/userfiles/file/88513002462.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161421f110889e---gudisazoganuxexej.pdfIn PDF document text
    • http://aostavet.it/userfiles/files/mugok.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16150c0fe475e5---79991951010.pdfIn PDF document text
    • https://acrgroup.nl/userfiles/file/tozefirekagogoxuxowigavo.pdfIn PDF document text
    • http://leguido.net/files/66043521755.pdfIn PDF document text
    • https://uslugiinzynierskie.com/eurostyl/photos/file/lepajezixilikes.pdfIn PDF document text
    • http://grupopiscis.com/upload/files/7725917377.pdfIn PDF document text
    • http://tbff-bygg.se/img/files/90572209394.pdfIn PDF document text
    • https://eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/xotor.pdfIn PDF document text
    • http://hodinovysoused.cz/upload/file/77895957092.pdfIn PDF document text
    • http://www.startservis.sk/novy/ckfinder/userfiles/files/50175188440.pdfIn PDF document text
    • http://clear-es.net/yamituki-n/uploads/files/lefiviwizewukejuzasut.pdfIn PDF document text
    • https://sabagdasarov.ru/upload/file/ralejarimanugido.pdfIn PDF document text
    • http://sghscsjamarai.org/guruhargobind/userfiles/file/gawabijofuwemojo.pdfIn PDF document text
    • http://idevoz.rs/files/kurinuzifa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=f9+movie+free+onlinePDF 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_off0000b314.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB314 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cb2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB2B 10156 bytes
SHA-256: 6efa63a041fe8493968ad04846169a92f0784e31dbab2ac84dac05f5f2f811d9
font_02_sfnt_off0000e1dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1DC 17152 bytes
SHA-256: 25b09058f18125afe4276777954eb7d6b9288842209d28ce2fcf30e746b0ef49