Malicious PDF — malware analysis report

Static analysis result for SHA-256 8891781b0705e83d…

MALICIOUS

PDF

84.2 KB Created: 2021-09-07 17:06:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: caf60b27f55424187f658d4b8dc06a9f SHA-1: f89b2577d2e8435e1415d10fb95afa23fdae127c SHA-256: 8891781b0705e83d3e1cdf2d7f354eaf311564f3e5af5c14c2951f499d04963d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various websites, many of which appear to be compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, suggesting the document is designed to leverage these links for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://crewmak.ru/uplcv?utm_term=comment+fusionner+des+fichiers+pdf+en+ligne
    • http://sibmaxi.ru/userfiles/file/44900516610.pdf
    • https://lawyerupsmart.com/tempimg/file/jifomagunojonewakizaf.pdf
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16094ac4bd70f2---77585789876.pdf
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c79a54a2189---piporinawob.pdf
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac7d0ad7a63---21830619556.pdf
    • https://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/2dff89b6ba149786c3d7d5ea159dd8a1/betakus.pdf
    • http://primethailand.com/ckfinder/userfiles/files/dageridusopifesajuxonowi.pdf
    • https://twr1115.net/files/fckeditor/file/66459692194.pdf
    • https://boucherienabli.com/uploads/FCK_files/file/44434636538.pdf
    • http://keitbg.com/images/files/gufufirakazoduk.pdf
    • http://artwatch.ru/userfiles/file/64629529492.pdf
    • https://www.ltgpartners.com/wp-content/plugins/super-forms/uploads/php/files/0c9a6b6bf602906cc5f0ebc0c76d12d9/81355901761.pdf
    • http://www.aunay-sous-auneau.fr/ckfinder/userfiles/files/57352103472.pdf
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16080ba33de890---besudolibimusizorejugawaz.pdf
    • https://udruga-invalida.hr/files/biwusaremoxejaranuteb.pdf
    • https://valenciamaids.com/userfiles/files/60389739038.pdf
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/2f834ad371888daff4da742e6f97eb62/1445433557.pdf
    • http://secondhandgraphics.com/usrfiles/file/82586099553.pdf
    • https://perfecthospital.org/ckfinder/userfiles/files/boxiranusazutamot.pdf
    • https://avistravel.ro/userfiles/file/dexaxodimigejid.pdf
    • http://g-shocktou.com/user_file/file/tazinofatoj.pdf
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a655a0a548b---jozuwaxibofutuk.pdf
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/a147703fadc2bc5ec21936e984e385e8/28458660830.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e1fa.bin
6e2c5825e05f2b30f6a217a059f196f00ea9900c8057fe34aedb8fe6c75cbb9b
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FA 18280 bytes
font_01_sfnt_off00010fdc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FDC 16792 bytes
font_02_sfnt_off000127f3.bin
4a0fe2dacf85c55b212262217413d59bc3ed501b8d42c8fd36d05456108e8dc5
pdf-font-stream PDF embedded font (sfnt) at offset 0x127F3 11036 bytes