Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8df534373f38747…

MALICIOUS

PDF

79.5 KB Created: 2021-09-23 19:12:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4507f755debae7f6b9533f0f510fbdb9 SHA-1: fe6c280c4a7839db27badd578f879f060e7bc7a6 SHA-256: c8df534373f38747ea49c7a7270a797bfdef3c722c2b5c8cb218eb1c763c41e4
156 Risk Score

Malware Insights

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

The PDF file contains numerous links, many of which point to websites hosted on compromised CMS upload storage, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://csc-021.com/userfiles/file/20210918034622_2t6hxe.pdf In PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/vazolizesa.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c56f0b9ba2---vajikivegev.pdfIn PDF document text
    • http://leadingedgecorporate.com/user_images/file/92947771657.pdfIn PDF document text
    • http://peoplefineart.com/assets/202109/files/20210912201026773319.pdfIn PDF document text
    • https://standsimulator.com/ckfinder/userfiles/files/22163462731.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/161444d885c6ef---30267439309.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/files/todadunaluvezidopuxiruval.pdfIn PDF document text
    • http://xn----otbb6ahq3d.xn--p1ai/ckfinder/userfiles/files/ralijixosiwijogifufezudax.pdfIn PDF document text
    • http://dental-forum.ru/userfiles/file/42338716236.pdfIn PDF document text
    • http://denda.co.kr/ckfinder/userfiles/files/retopewosewemuxo.pdfIn PDF document text
    • http://quangphong.vn/uploads/image/files/37650285845.pdfIn PDF document text
    • http://allseasonsart.com/uploads/fck_uploads/file/96928058921.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613c6438d2bee---40973986136.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/9fgej7pdpqmausd7uarssko6go/69247175280.pdfIn PDF document text
    • https://samsungdvm.net/upload/ckfinder/files/6016053898.pdfIn PDF document text
    • http://shceping.com/upFile/photos/2021-9/file/89633887644.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147f21c6e062---fojuwevigepuzozivavifelas.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///20210913151023_904052659.pdfIn PDF document text
    • https://chulintemple.house-well.com/CKEdit/upload/files/juwepozexogoxav.pdfIn PDF document text
    • http://mikailang.com/userfiles/file/20210910114719_493037156.pdfIn PDF document text
    • http://taigesw.com/upload/files/loburisubotefusofame.pdfIn PDF document text
    • http://www.trackls.com/application/ckeditor/ckfinder/userfiles/files/nowetoxumipuxomabivazo.pdfIn PDF document text
    • http://kondicionery-dzerzhinskij.ru/upload_picture/file/xorot.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=choplifter+hd+androidPDF 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_off0000d12c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD12C 10456 bytes
SHA-256: 9e4c51ef56b5590e3b44a968ecf56de15b24bb93c3a36d2e51dd25baa84cc609
font_01_sfnt_off0000e8d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8D0 17664 bytes
SHA-256: d17341c4782dad454fccac9f0e9b401f276c1d50208c1192faab95c77d87c37c
font_02_sfnt_off000116da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1