Malicious PDF — malware analysis report

Static analysis result for SHA-256 36628a4d5e850aa9…

MALICIOUS

PDF

75.7 KB Created: 2021-09-01 09:08:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a24b3571dc99b2145e17e8b32e3d96bd SHA-1: b422745dec32fa3d960e8b0346cf5c551eaba97d SHA-256: 36628a4d5e850aa940871dadc51fc44bd175a1c138203ef262241798f814bf1d
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to compromised CMS uploads and disposable hosting. These links likely lead to further malicious content or phishing pages, aiming to trick users into downloading malware or revealing sensitive information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://kaitosushisb.com/uploads/files/64481684139.pdf In PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160756ce3efc4d---digupiwosariwozezusaroze.pdfIn PDF document text
    • http://przedszkolenisko.pl/userfiles/file/kulibodapudekubagokawit.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/73469064798.pdfIn PDF document text
    • http://clarksville.net/wysiwygfiles/file/xineruzabebokavitovu.pdfIn PDF document text
    • http://tzoetemondje.be/uploads/files/paweduroji.pdfIn PDF document text
    • http://clairvoyantinfotech.com/demo/images/povovalanaropexudelal.pdfIn PDF document text
    • http://lubrifianti-auto.ro/files/file/rogiwix.pdfIn PDF document text
    • https://detskeihriska.eu/ckfinder/userfiles/files/54420038919.pdfIn PDF document text
    • http://menafundinfo.com/userfiles/file/debuvagulubiwowito.pdfIn PDF document text
    • https://actorconseil.com/files/file/xiwaximewikozulukujimu.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/83a79e120a9164984febe3e0125a854f/22489563438.pdfIn PDF document text
    • http://rld-carbon.ru/file/63321248943.pdfIn PDF document text
    • http://thecuriosityshot.com/78772151761.pdfIn PDF document text
    • http://gaziogluenerji.com/images_upload/files/vigujuzefivo.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607adee2a3e95---foxezedilami.pdfIn PDF document text
    • https://dialogueinpraxis.net/files/docs/9068138756.pdfIn PDF document text
    • http://ebus.cn/up_file/file/poxixadativutu.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/297432801.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/16074f8d2456cd---49880530308.pdfIn PDF document text
    • http://fotobambagiotti.it/userfiles/files/zudipato.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=each+other%27s+backPDF 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_off0000be11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE11 10336 bytes
SHA-256: 4eabec61a5063fc9ceec0dd7c469c16a490aba1a52416469b43fe791e372c6a0
font_01_sfnt_off0000d5a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5A1 20020 bytes
SHA-256: 8ed60d11cf0deb954283804e02168e470224a699669c26fe8ac9d38f2a977b17
font_02_sfnt_off000108f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108F7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1