Malicious PDF — malware analysis report

Static analysis result for SHA-256 17712ce3cbf08e43…

MALICIOUS

PDF

74.8 KB Created: 2021-06-19 09:13:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 8e93242dce7e7b8325644f432d038dc3 SHA-1: a77b2af6f9c6f3beb483be0aa1a91b97cc1f442b SHA-256: 17712ce3cbf08e4365f591fd1e2a150919bf8ee5ce374846a20b3c103ae7d646
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites and other domains, likely for phishing or malware distribution. The presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest this is the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://archism.ru/uplcv?utm_term=c2+sans+fight PDF link annotation
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/9adutsi6vaa00ki10sk9oqcrb6/62262502005.pdfIn PDF document text
    • https://gyandeepjkss.org/userfiles/file/11385669894.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/28300fd8f796733daed08849d666a532/bakigakuvulagesusuz.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/nunatowidef.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609e3d40ef582---92239086177.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609074f374f1e---xugekuxo.pdfIn PDF document text
    • https://gachbinhduong.com/upload/file/fonisudoxutakebekovim.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b2d2bb36ef8---benuvotaxiwejadused.pdfIn PDF document text
    • https://landi-bg.com/images/file/31689376862.pdfIn PDF document text
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/16080036776c00---19514247380.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c47b1147a6---xedilibaratevuwaz.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/1609c46e0a4f04---53232933317.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608a1578e6c26---fosezisebexajopetutir.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/ddd46ecadcc89af3e9a25ffc1bf0103b/fekadugoli.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/fibitit.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA88 4936 bytes
SHA-256: 7f56342ca7cb7574fb58b78d98f5c943a65fb273075e42668e65f515eb307bff
font_01_sfnt_off0000eb50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB50 2052 bytes
SHA-256: ed51b0ebd4fde5ef4ac091722a637ff45f7f9295ddfd49491fd26536bd17ce32
font_02_sfnt_off0000f406.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF406 12320 bytes
SHA-256: fd6ee16c3896d600752a46a9b802433cbe573a1b04aa33f6e5d4305837012b07