Malicious PDF — malware analysis report

Static analysis result for SHA-256 d57c39d4c49fa772…

MALICIOUS

PDF

100.8 KB Created: 2021-09-01 09:22:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6b9e4fe22b9d408cc0649e7c051f8c88 SHA-1: 1f8d3f180334b5195daea7900e2aaad68f0d7ad3 SHA-256: d57c39d4c49fa772d649f746a7fd11c8ca06f01bd604017ac872b57cf8dc5f70
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised CMS platforms, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards an attempt to exploit users via embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://girisimhaber.com/uploads/file/zosuselefenupizegek.pdf In PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608dbe2974a05---gafogivaxewixixa.pdfIn PDF document text
    • http://ambulatorioveterinarioilghirlandaio.it/userfiles/files/32647990457.pdfIn PDF document text
    • http://jncs.kr/page_data/file/20210601093652.pdfIn PDF document text
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/657e8225bf259866b8966fd7eb33181c/boxamerogaxozumaleb.pdfIn PDF document text
    • http://bdn10.cz/files/file/35925424265.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/pf5al1h8b7v3e7t6k0c97qgumo/70423857397.pdfIn PDF document text
    • https://kocarbon.vn/luutru/files/dofobeb.pdfIn PDF document text
    • https://www.highlandernepal.com/assets/ckfinder/userfiles/files/91794889517.pdfIn PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/b6d63508affc39f8a6153322ab0894a1/wopov.pdfIn PDF document text
    • https://mimpishio1.com/contents/files/zuvuteba.pdfIn PDF document text
    • http://statsale.com/data/upload/ck/files/4275446568.pdfIn PDF document text
    • http://massvt.sk/editor_uploads/system/files/98024433806.pdfIn PDF document text
    • http://www.tobywells.org/media/fckdir/file/18322868097.pdfIn PDF document text
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/5c7ac1174b6d5ffaa953832cf8577f1c/579419805.pdfIn PDF document text
    • https://deedpoll.sg/wp-content/plugins/super-forms/uploads/php/files/7d9221eb876a6a9764736c24dc9604d9/jijunozagux.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f2548983430---suzakagesisebetemol.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb6b847a444---segolefodi.pdfIn PDF document text
    • http://samtekelektrik.com/files/63730001397.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607e9f0945481---xigosevemal.pdfIn PDF document text
    • http://self119.net/upload/userfiles/2021/08/files/210807033058.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ab43a10357c---82544916739.pdfIn PDF document text
    • http://centreforeffectivecoaching.com/media/file/gijulasexijafokawo.pdfIn PDF document text
    • http://arunimaflavours.com/userfiles/file/giwitubozumesuxazum.pdfIn PDF document text
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/1ff15f1a65169885a38f023e59ee26ad/kebodaxiwarajuvakaji.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=ccc+course+pdf+in+englishPDF 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_off000123c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123C9 10768 bytes
SHA-256: 4a243af850536a81e119f71d81efd26f9fe74fc0bbebdf1c34c10a6e04384f08
font_01_sfnt_off00013c33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C33 18892 bytes
SHA-256: 287281a5cd760ef9224a7bcc8117757c693ff0d183c749928ac813793b7692c9
font_02_sfnt_off00016d47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16D47 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1