Malicious PDF — malware analysis report

Static analysis result for SHA-256 1873b9a107b93999…

MALICIOUS

PDF

75.3 KB Created: 2021-09-07 18:14:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-02
MD5: 1f0b475810ce56207c458d1dff4aca0d SHA-1: ff1646fd3c59bdb79d715c73f50bc52808c7fefd SHA-256: 1873b9a107b93999e36bbd02092e59b9b4d99e2f145942340c5580ed3a0cad60
104 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • 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://poiskvod.ru/images/file/foluzu.pdf In PDF document text
    • https://posaonakosovu.com/ckfinder/userfiles/files/sobot.pdfIn PDF document text
    • https://www.funes.gob.ar/ckfinder/userfiles/files/19941442730.pdfIn PDF document text
    • https://manpowernepal.net/ckfinder/userfiles/files/lilarekoxirovumutare.pdfIn PDF document text
    • http://safires.cz/ckfinder/userfiles/files/vejitukop.pdfIn PDF document text
    • http://abwingssuffolk2.com/uploads/files/9726293530.pdfIn PDF document text
    • http://soeurs-scjboran.fr/soeurs/upload/files/pafijine.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096b8b540993---49083980876.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/ab05f29f06d1edb42041bb39b05c88e1/69479760497.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a713efe37f0---98908406269.pdfIn PDF document text
    • http://birkhoffhi.com/userfiles/files/1266331902.pdfIn PDF document text
    • http://arci-mp.fr/admin/File/vezavujexabifuwatulubige.pdfIn PDF document text
    • https://anglarill.net/userfiles/file/wobuvudofapomizo.pdfIn PDF document text
    • http://casinodanmarkjackpot.dk/userfiles/file/34941914477.pdfIn PDF document text
    • https://neavocats.com/wp-content/plugins/super-forms/uploads/php/files/31574ae40b01f9bc095ee432e2e361da/kotikinupopazobikino.pdfIn PDF document text
    • http://jrmhandling.nl/upload/file/notitusosuxifoj.pdfIn PDF document text
    • http://svx.su/ffile/file/kuwarov.pdfIn PDF document text
    • http://cityclick.it/userfiles/files/65346469647.pdfIn PDF document text
    • https://landi-bg.com/images/file/saxaw.pdfIn PDF document text
    • http://remproekt-m.ru/admin/ckfinder/userfiles/files/77416303938.pdfIn PDF document text
    • https://bczenekar.hu/files/file/23693018010.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607e42583e928---wiwuti.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/7fjgnie7tt9agu3k24p0p38347/bunepewegojupimopu.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/49888f4c58094a814a666a97e80abadb/moxitikanajaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=laksa+king+menu+pdfPDF 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_off0000c4cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4CF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dce1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCE1 16728 bytes
SHA-256: e45ad46a0a260696c5d4c3ef1ba7e43acf72b74c1ab37100b27149ef298b6159
font_02_sfnt_off000107ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107AC 10624 bytes
SHA-256: da501235e212f52b3dc332b278419fb0c4d6588fed96ec719b30bebd963cfc13