Malicious PDF — malware analysis report

Static analysis result for SHA-256 621f9c41833b09a7…

MALICIOUS

PDF

88.9 KB Created: 2021-06-10 13:01:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 3e55bbf54c69c5dee3998345470aa316 SHA-1: 8b5bb2c3f0829adb48074e0a8ec1cb3222c7d8dd SHA-256: 621f9c41833b09a7323c3db9068f96257f45f64dc1996c202793d7636c559d55
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to various domains, many of which are hosted on compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a malicious document designed to exploit users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://queure.ru/uplcv?utm_term=merge+photos+into+one+pdf PDF link annotation
    • http://taxicityplus.ru/userfiles/file/4339366433.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/38519767181.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/da5ef901672910a172c648a9e0ef19df/42769064610.pdfIn PDF document text
    • https://diaochue.vn/userfiles/file/lujij.pdfIn PDF document text
    • http://self119.net/upload/userfiles/2021/06/files/210604210204.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e6765614a0---risewaja.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160bf40c2c47e4---36269023577.pdfIn PDF document text
    • https://remoteworkerclub.com/wp-content/plugins/super-forms/uploads/php/files/fedaa13d178804d37c12ee11bcf90039/laderowo.pdfIn PDF document text
    • http://stonebreaker.at/20084834768.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/hhr0ttk0gk4gr38uvcg5dj7k34/25122146960.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a2a0c0d565d---31857980528.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/ee5c87e49e2f5795dc8637876c7ec3e0/16710740310.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/12490998050.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/17931376245.pdfIn PDF document text
    • https://anukulagrotech.com/userfiles/file/82258656496.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fa8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA8A 5064 bytes
SHA-256: 48be98ec769bd365dd69f1e326f45453493b563099f5c916758d2302664312c1
font_01_sfnt_off00010bc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BC9 3092 bytes
SHA-256: bda428cfc9d8f504dc5c54fc14760949cf189a193a09f0aad8d2121a2832ac0f
font_02_sfnt_off00011907.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11907 11516 bytes
SHA-256: 0dff3ace4aa8be36033fdc6dbc6b32195f38e244137920db76d05a5ca4321881
font_03_sfnt_off00014083.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14083 16336 bytes
SHA-256: cb8b0c3b75634a3ac40028f3142d2b99dbff9c8bfe93654f62892c2eba89f065