Malicious PDF — malware analysis report

Static analysis result for SHA-256 28fd57b136d75533…

MALICIOUS

PDF

83.3 KB Created: 2021-09-13 20:29:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7e55df8466bcbcb4d445619b7cf2a79e SHA-1: c5896e5556bf58091ee524db60c363f660ede159 SHA-256: 28fd57b136d755330de3aa0efd8a41392d2519b6dd5e5088dc083d668f98199e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to disposable domains, and is flagged by heuristics as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.ags-sib.ru/ckfinder/userfiles/files/zepukogenazitusipofiliwi.pdf In PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/zevubiwilifi.pdfIn PDF document text
    • https://clubkdo.fr/img/pics/files/7908902417.pdfIn PDF document text
    • https://299-45.com/CKEdit/upload/files/47543843128.pdfIn PDF document text
    • http://coffee33.ru/archive/file/87296548037.pdfIn PDF document text
    • https://9ja-bet.com/userfiles/file/5687986279.pdfIn PDF document text
    • https://balbok.net/admin/ckfinder/userfiles/files/lajopotude.pdfIn PDF document text
    • http://zatoodesign.com/userfiles/files/vukevuwemajoxa.pdfIn PDF document text
    • http://gaushalango.com/uploaded_files/userfiles/files/82960164712.pdfIn PDF document text
    • http://mgrima.com/files/file/kupebemuvilijenajeje.pdfIn PDF document text
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec0a46d6da---venaterijatikoxakivanakeg.pdfIn PDF document text
    • https://www.greenlakecruises.com/ckfinder/userfiles/files/5575345366.pdfIn PDF document text
    • http://s13cf5ef.alojamientovirtual.com/ropadefutbolbarata/userfiles/file/kevoxiremejifikogawe.pdfIn PDF document text
    • http://myphamso1.net/uploads/files/4684307342.pdfIn PDF document text
    • https://tauthuy.vn/upload/files/xubafu.pdfIn PDF document text
    • http://thechelseaff.com/user_uploads/files/78262165383.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613773f7cfb38---26321782422.pdfIn PDF document text
    • https://orrizon.ru/images/file/vikazuzisizeziwagok.pdfIn PDF document text
    • https://onutglen.com/caningest/images/file/7973949655.pdfIn PDF document text
    • http://qdsenfeng.com/data/files/kinivoja.pdfIn PDF document text
    • https://tidymoney.com/ckfinder/userfiles/files/vaxaliritadivamutataj.pdfIn PDF document text
    • http://palletgoanloi.com/img-dn/files/47684487877.pdfIn PDF document text
    • https://iva-vietnam.com/userfiles/file/64644773555.pdfIn PDF document text
    • http://gespk.com/userfiles/file/35772244387.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=putlocker+train+to+busan+2PDF 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_off0000db56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB56 10676 bytes
SHA-256: 0b65f1b989d360837cf1955703cdb933155c3bd8bf24ab1d45fad4bfdb791cba
font_01_sfnt_off0000f400.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF400 18956 bytes
SHA-256: ccb6905c279a39e1abaa1ec4bbc80102ba7dee2d354d6116ba4f83957b40feb0
font_02_sfnt_off000125f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1