Malicious PDF — malware analysis report

Static analysis result for SHA-256 8533216b7ffe17ff…

MALICIOUS

PDF

71.4 KB Created: 2021-09-25 11:57:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d1f2a7510513259e53fc17e1de83e434 SHA-1: 4672f0a9f2909c90af4134d14db248b30a5a100a SHA-256: 8533216b7ffe17ffbb21d128d442fe6811a2564192c5d9395395b7f8bc2ebd82
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous external URLs, several of which are hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://www.rajpuc.pl/pics/file/59619455321.pdf In PDF document text
    • http://jhdljz.com/userfiles/file/1631750972.pdfIn PDF document text
    • https://kampusogrenciyurdu.com/file/95483271811.pdfIn PDF document text
    • https://www.hosotte.com/ckfinder/userfiles/files/72045414772.pdfIn PDF document text
    • https://jogamiskolc.hu/ckfinder/userfiles/files/94653399835.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/3c5479750d096e9d4eee877521402c93/91175912449.pdfIn PDF document text
    • https://termofriz.rs/files/63911161146.pdfIn PDF document text
    • http://geometrabottero.it/userfiles/files/buxig.pdfIn PDF document text
    • https://baongochoa.com/upload/file/limaperim.pdfIn PDF document text
    • http://usarsenal.it/userfiles/files/juwevavajaperetiraz.pdfIn PDF document text
    • http://msinziniering.com/userfiles/file/fufavojeruxugezonobubed.pdfIn PDF document text
    • https://divanich96.ru/admin/ckfinder/userfiles/files/49362020652.pdfIn PDF document text
    • https://thietbixanh.net/uploads/files/91450089742.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614024c6518e8---tabatobu.pdfIn PDF document text
    • http://apex-architect.ru/images/file/gosulu.pdfIn PDF document text
    • http://anoh.net/pds/userfiles/files/vewef.pdfIn PDF document text
    • http://korealabels.com/ckfinder/userfiles/files/zuwunumosegamerejipipalog.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/kj3qenipm8vd7n2hn8crtct2k3/87278946141.pdfIn PDF document text
    • http://bratislava.topenglish.sk/app/webroot/gallery/files/55923697538.pdfIn PDF document text
    • http://mojaksiegowa.net/userfiles/file/juduna.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/56544773308.pdfIn PDF document text
    • http://vitalbafitnessclub.eu/userfiles/files/vajujuliduwox.pdfIn PDF document text
    • http://newworldss.com/uploads/file/gurobufelinisoxapurox.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=como+saber+cual+es+mi+cuenta+google+androidPDF 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_off0000b383.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB383 16736 bytes
SHA-256: 7c4bd72eb895eada419a58f4de9d1107677cce1ab1bfea93041cd74c02fe2016
font_01_sfnt_off0000de14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE14 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f62b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF62B 10984 bytes
SHA-256: 4c31c7c9c7063b578d482c76e5e58ce990a09a9a78b95317789e7dcaf3526a3d