Malicious PDF — malware analysis report

Static analysis result for SHA-256 def8467bba2dda88…

MALICIOUS

PDF

87.6 KB Created: 2021-09-07 23:08:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 3e01798db2f7009e2e6f6f384f7ef497 SHA-1: 6ee682b971111ddec0b836b89153823f38fce32a SHA-256: def8467bba2dda88550671148d3ae4d957c230a4c50e5437bfc6afbc16959160
164 Risk Score

Malware Insights

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

The sample was flagged by multiple heuristics as malicious, including a critical ClamAV detection and a high ML score. The presence of a 'download button' lure and numerous links to compromised CMS upload directories suggests a phishing or malware distribution attempt. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, likely serving as a container for these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://prunay-en-yvelines.fr/ckfinder/userfiles/files/49228439405.pdf In PDF document text
    • https://cmetrix.net/ckfinder/userfiles/files/joxizuruj.pdfIn PDF document text
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/5esu81nmdcvubbdpkr2bkc0kt3/zitizuvonulenunome.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4f6eca4a8---92778291576.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d4f69cf12f7---37067396141.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/00f0b3bd77454fae5773ee6d62a94088/13574686505.pdfIn PDF document text
    • https://bbu.vn/Images_upload/files/72797710866.pdfIn PDF document text
    • https://emauto.lv/index/images/up/file/nogadutu.pdfIn PDF document text
    • http://heydarbaba.org/resimler/files/81695615067.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/893665def771af8407d538132a9e7686/poxutafivo.pdfIn PDF document text
    • http://stlukesmn.org/clients/17773/File/nukevofirolegoma.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/rp0ammh5d1a0svrj55vv7rt8s1/21641017717.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfc2d2465c1---86864091921.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/160ff02d1d33fe---kotabekomujemidovopurewe.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/f5c7e45388865b54973bde1b01074b31/bitabapifejarepup.pdfIn PDF document text
    • http://asude.istanbul/ck_images/files/vukenekenerujuwesaguzu.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160b7cd9ae7940---pixezejeruduxeditob.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160757123aff93---samerisedowiviforol.pdfIn PDF document text
    • https://strechybenesov.cz/content/vazub.pdfIn PDF document text
    • http://taeguektour.com/FileData/ckfinder/files/20210712_2051F64803AE9195.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612c3152a3bc9---84208671761.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610c8bfb7b9e0---86274760468.pdfIn PDF document text
    • http://melvin.cz/data/85135796630.pdfIn PDF document text
    • http://agiusfuneraldirectors.com/files/file/15226241151.pdfIn PDF document text
    • https://samtee.com/admin/images/file/37792704149.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=cfmoto+cforce+600+service+manualPDF 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_off0000e78d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE78D 10984 bytes
SHA-256: 0558d150055c42f3116a7ae3a154d4e6b1a34579ec0e54d8596bef0eb7424657
font_01_sfnt_off00010120.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10120 21624 bytes
SHA-256: aa2917681a0daade062034331d760ba10e44ba86cbd550582ccb64ab6f9ddfba
font_02_sfnt_off00013891.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13891 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1