Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8cde08b7237876c…

MALICIOUS

PDF

79.6 KB Created: 2021-09-16 14:11:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 707e7295e4891a0126ac282cefdc55ed SHA-1: b40b1404fe5a3b8eba0338d44670e2ad8877a181 SHA-256: a8cde08b7237876c8a51e248875868572bc6f4e976b213d743de8a62ac4c8e0f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of links, many of which point to websites hosted on compromised CMS platforms or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or redirection to malicious content. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool, offering no direct user-facing content to analyze.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://gordostcrista.ru/userfiles/file/bimapenipawowifavo.pdf In PDF document text
    • http://svx.su/ffile/file/tabixubemetekefolakewore.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/161391d64df35c---97120878580.pdfIn PDF document text
    • http://www.mmalappeenranta.com/tiedostot/files/pimafaxobawi.pdfIn PDF document text
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/94897299974.pdfIn PDF document text
    • http://massimomoroni.it/userfiles/files/81566787484.pdfIn PDF document text
    • https://bizimpin.com/calisma2/files/uploads/meriruvuzikogisejevuwobe.pdfIn PDF document text
    • http://otestmanager.org/club/data/userfiles/file/20210911043759.pdfIn PDF document text
    • http://artgraf24.pl/userfiles/file/fusadanexekemu.pdfIn PDF document text
    • http://4rrecycle.com/files/file/71988784488.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/3q7giv0cbj6uk6e8dh5csk8m5r/6958275724.pdfIn PDF document text
    • https://marblo.ph/app/webroot/img/files/97454326107.pdfIn PDF document text
    • https://homecareangels.ca/files/files/files/gofomogevetigapized.pdfIn PDF document text
    • http://cableesmaltado.com/d/files/gukir.pdfIn PDF document text
    • http://shangrilatheshow.com/ckfinder/userfiles/files/ziwuvutejesofekuta.pdfIn PDF document text
    • http://conelser.hu/fck_uploads/file/39604113796.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/63d88a414469ac5efa331275481a3c30/vigatumozetulej.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142da76745bf---89980803846.pdfIn PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161417b4e4fea9---gerajivosogifuzotinigofoj.pdfIn PDF document text
    • http://www.gieskestukadoors.nl/ckfinder/files/files/13115057619.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161387f754a334---92273578436.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=latest+gba+pokemon+gamePDF 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_off0000d1d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e9e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9E9 18380 bytes
SHA-256: 13cd20ef54da758c009f7204e642aacd197b6ad95694ca03119cbf994a4c8e7d
font_02_sfnt_off00011961.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11961 10548 bytes
SHA-256: f313921ecb159ad822c1a0d8f9f59cc9cdb45dee43b1ec8b1a65ac14c61ed506