Malicious PDF — malware analysis report

Static analysis result for SHA-256 fce5adb07c4f107f…

MALICIOUS

PDF

72.0 KB Created: 2021-09-27 19:10:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: a5be8a323c00e7c10559631f73e1d908 SHA-1: 0b06b4c636a7cb44807640b6db5fcbea851e58a0 SHA-256: fce5adb07c4f107ff8acafc94a5e5f4faa4b977d7b8390acb14ca7d797295c7e
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of external links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute traffic. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous URLs suggests an attempt to lead users to potentially harmful content or phishing sites. No scripts were extracted, and the document body was unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • 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://philabc.ru/uplcv?utm_term=how+to+make+screen+saver+in+android PDF link annotation
    • https://verlauf-ekb.ru/admin/ckfinder/userfiles/files/61038161996.pdfIn PDF document text
    • https://synersys.fr/contenu/file/jogemeguz.pdfIn PDF document text
    • http://frchem.cn/upload/files/81489848019.pdfIn PDF document text
    • https://rpdev.org/ckfinder/userfiles/files/linek.pdfIn PDF document text
    • https://enilubricant.hoakhanh.vn/uploads/image/files/1239439596.pdfIn PDF document text
    • https://mygrind.ie/userfiles/file/83561453217.pdfIn PDF document text
    • http://chirineli.com/img/lib/file/gorerejopufavuz.pdfIn PDF document text
    • http://sarljarry.com/userfiles/file/23171174821.pdfIn PDF document text
    • https://virtualpulse.eu/UserFiles/file/96190092873.pdfIn PDF document text
    • http://christschoolblr.in/userfiles/file/vemilugugorake.pdfIn PDF document text
    • https://vibingvibes.com/userfiles/files/viwifinoberupiwuriwexunig.pdfIn PDF document text
    • https://nodka.eu/ckeditor/ckfinder/userfiles/files/xageviniguwibororukon.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c2fe6a7a84---moxosa.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/87vpjrmjdhbi1c31jp1cgre293/82389034008.pdfIn PDF document text
    • http://15881588.com/ckupload/files/nutibugewapemevigumi.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614e5b6786c27---3278233058.pdfIn PDF document text
    • https://dodatkireklamowe.pl/web/uploads/files/99844664410.pdfIn PDF document text
    • http://bycongroup.com/UserFiles/file/77039374977.pdfIn PDF document text
    • http://btsoft.vn/uploads/files/73235739947.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/46039766713.pdfIn PDF document text
    • http://pincailight.com/zk/UploadFile/file/2021092723160573499.pdfIn PDF document text
    • http://progetec.org/userfiles/files/44421164503.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/1614cbdfb69f36---60922858223.pdfIn 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://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_off0000b3ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cbfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBFC 17232 bytes
SHA-256: 84fb3831c2ff9663283459af79acd65aae9db1fe1c5fa7431e66d89a218b0f04
font_02_sfnt_off0000f7bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7BD 10720 bytes
SHA-256: 78cacb3d5cf70bbee918effaefc1045a1c758707e2fcf0811f5b6dba17aceecc