Malicious PDF — malware analysis report

Static analysis result for SHA-256 507c276bac7d363c…

MALICIOUS

PDF

101.1 KB Created: 2021-09-08 03:36:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 5fc3ee2d1494ca1064fae8d5563f9680 SHA-1: 1bb65b98459aa7d7dce5cb7dc8be99e4adc63c9d SHA-256: 507c276bac7d363c22ff455982a8bd733f1bff395fc6bf03bdf36a34514f04b0
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous URLs, many of which are hosted on compromised WordPress sites or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://eperon-kochersberg.com/img_db/13435984876.pdf In PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/161032ea2994fa---53726536218.pdfIn PDF document text
    • http://www.gdchgs.com/admin/img/files/18392667907.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16084dbe9442b1---piguv.pdfIn PDF document text
    • http://alexandersorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nufota.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/j3dq69vdnoei5tjrh9qgqiuo9u/farasavulomoruxuv.pdfIn PDF document text
    • https://thietkeweblongan.com/upload/files/zunizavoju.pdfIn PDF document text
    • http://sasolution.kr/userfiles/file/48753820728.pdfIn PDF document text
    • https://cuacuonbentre.com/upload/files/28447041771.pdfIn PDF document text
    • https://asi-filter.pl/files/file/kobivuzukala.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/16088468d62fdd---77036213387.pdfIn PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/b0a7d500909cd88c49d42a696e8ead2f/ranosubedogesaxif.pdfIn PDF document text
    • https://samajsutra.com/userfiles/files/zuzib.pdfIn PDF document text
    • https://caribemed.com/userfiles/file/vubitoramapobavoli.pdfIn PDF document text
    • http://chiangmai-clean.com/user_img/files/gipoxa.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/vc5doaqtaaqo3i404drfm0rns7/6884972173.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160a170f8baf19---ravutinakitimevuxuwo.pdfIn PDF document text
    • http://mabo-meccanica.eu/userfiles/files/1978846276.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/79ee424833f897d6c014618d32421ad3/4516948800.pdfIn PDF document text
    • http://www.hermosabeachbungalows.com/userfiles/files/tutikasinedopik.pdfIn PDF document text
    • http://kiszelyugyvediiroda.hu/docs/file/zisinusepuxavebopezon.pdfIn PDF document text
    • http://tsnpharma.com/upload/files/bojoku.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160c97954befbc---15112747394.pdfIn PDF document text
    • http://nguyenquangcomputer.com/upload/ck/files/wipuvedewowebaxu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=libro+de+adivinanzas+y+trabalenguas+para+ni%C3%B1os+pdfPDF 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_off00011771.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11771 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012f88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F88 11316 bytes
SHA-256: c46843b5109cceafce9b3d5aa1fdd55f3e4e433487d388b6cfa560f72c934572
font_02_sfnt_off000149a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x149A9 23236 bytes
SHA-256: 445478d01a7fe898748d4107c6655bfefd8e25a5e9a6d8dd362bdd8c938dc283