Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff4b24df2128d317…

MALICIOUS

PDF

74.3 KB Created: 2021-08-16 03:52:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2d6d3e342997e06335dc37730ce3f2ed SHA-1: 1a5c04b7d3be3c1278021aeefe471d15c721f97a SHA-256: ff4b24df2128d3171a3d0bdbdc6d068c579f1221fe7792c4ba8404e590a4c5e9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high probability of malicious intent. It functions as a link farm, directing users to various compromised websites and potentially malicious content, as evidenced by the numerous external URIs and PDF link farm heuristics. The presence of embedded URLs suggests an attempt to redirect users to phishing or malware download sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://ketchas.ru/uplcv?utm_term=hsk+standard+course+5a+workbook+pdf+free+download
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/67c22cb098bac66415c5b0357beda51c/fuxuragak.pdf
    • http://tz5168.com/uploadfile/image/2021/05/30/file/20210530_123252_197.pdf
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b01a0acc8bf---15279139404.pdf
    • https://condominiovillage.com/userfiles/file/25705952504.pdf
    • http://samrayburnclassof1980reunion.com/clients/873185/File/89215066943.pdf
    • http://someteme.com/archivos/_20210710045506.pdf
    • http://firewheels.pe/userfiles/file/jatapibunomowareme.pdf
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/b091660c14571caf4eccf6d553e9936b/11197607113.pdf
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607aa55075a35---19789195228.pdf
    • http://statsale.com/data/upload/ck/files/87968495613.pdf
    • http://federalwayhighschoolclassof1970.com/clients/8/8c/8ce2019516a67423f07d8eefa67dd611/File/danutezepuxusesujigovopap.pdf
    • https://mimpishio1.com/contents//files/40788219567.pdf
    • https://iominneapolis.com/wp-content/plugins/super-forms/uploads/php/files/ede884ad4b66be06d6e7cfe829c1edc0/70165709735.pdf
    • http://feach.ie/images/uploads/file/95057666635.pdf
    • http://asiadomainstore.com/userfiles/file/jepakoruvidedofokomu.pdf
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2c4c8d2491---tevugogup.pdf
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb02d2178dc---16688552752.pdf
    • https://atpl.aero/ckfinder/userfiles/files/pifugifanuleguz.pdf
    • http://sk-uralstroy.ru/uploads/files/71694241878.pdf
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b24720202dc---lowitirimadujuguni.pdf
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610d6a5e5ae17---73716972891.pdf
    • http://wwstationery.com/files/file/xegosilurog.pdf
    • http://lapawan15.com/shop/fck_file/file/95707596923.pdf
    • http://webinaris.org/ckfinder/userfiles/publics/files/jekiribagidolu.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_off0000bed8.bin
353c5b87b8cacdd6a30cc61031446fd1441b5495b6eab4ef11c49735f73e8f61
pdf-font-stream PDF embedded font (sfnt) at offset 0xBED8 16156 bytes
font_01_sfnt_off0000e885.bin
927a01ab662799daa928ac49a2d8301380286ebdc6e87b50d83a99db5426cdf1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE885 11064 bytes
font_02_sfnt_off00010254.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10254 16792 bytes