Malicious PDF — malware analysis report

Static analysis result for SHA-256 e7aa6cd71d405948…

MALICIOUS

PDF

87.0 KB Created: 2021-06-29 23:52:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 8d9e32e6f9c40c7e9c902a2e78f63a17 SHA-1: 856fb7bb6d708670d841e887a1d29d4e53eec19d SHA-256: e7aa6cd71d405948b086bd5669fec20ccc8953628b463043fe6726fe76ca6bbd
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting. The document body is unreadable, but the presence of numerous links to potentially compromised sites suggests a phishing or redirection attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://ooo-kenk.ru/userfiles/file/17442483809.pdf In PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c995a9eda26---12814061341.pdfIn PDF document text
    • http://projectbudapest.hu/wp-content/plugins/formcraft/file-upload/server/content/files/16075aef248650---69063097284.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160d23cf6811cb---97299443894.pdfIn PDF document text
    • https://stmarys-perthamboy.com/upload/File/mewowovawedowafebelesuvux.pdfIn PDF document text
    • http://mya1fc.com/files/ckuploads/files/19397288485.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/47be4b815f8ef79a848849aff7a6ca69/7027382060.pdfIn PDF document text
    • http://sherwoodchambergolf.com/ckfinder/userfiles/files/37805048538.pdfIn PDF document text
    • http://lltsg.com/uploadfile/file///2021052907225431.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c74b71c7a3---badogamalirobatage.pdfIn PDF document text
    • https://cedarcreeksauce.com/wp-content/plugins/super-forms/uploads/php/files/d7adb2cfb920257b49ff2ab5f72f455d/lupud.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a99d7151824---gujikunav.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc44c41cce---vuwav.pdfIn PDF document text
    • http://somsit.com/ckfinder/userfiles/files/33210227106.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/fq5975env3hvu55pheqhg84iod/kafogel.pdfIn PDF document text
    • https://bonacorsi.it/file/12125947234.pdfIn PDF document text
    • http://alexanderjamesbackcatalogue.com/userfiles/file/metorobudegamuse.pdfIn PDF document text
    • http://zoltysnieg.pl/pliki_wyswig/files/98633695971.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa081470108---zuzuzus.pdfIn PDF document text
    • http://dgjst.com/upfile/file/59925379941.pdfIn PDF document text
    • https://angelsforwarriors.org/userfiles/files/69479373657.pdfIn PDF document text
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/8f99eecd79b8fbf795e1e8d7625fb2b1/59800051312.pdfIn PDF document text
    • http://omni-links.com/images/blog//file/1284241299.pdfIn PDF document text
    • http://canxetaianhduc.com/images/file/nolovililewonub.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/16078620634cbb---4926233077.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=work+efficiently+meaningPDF 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_off0000ec7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC7E 18168 bytes
SHA-256: 2b5139d798d66aee3c5664ca3a6cb9fe458d71db4595beefa5c31839f35c438b
font_01_sfnt_off00011c4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C4A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013461.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13461 10708 bytes
SHA-256: fcecf8e351125bce9ccce5055b39cb2e7f90a6028cd6c4bf54a1add410662aba