Malicious PDF — malware analysis report

Static analysis result for SHA-256 72c9256510c013b7…

MALICIOUS

PDF

73.3 KB Created: 2021-09-01 08:37:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: f75e8c3e1268776d54c13bbedc49bdff SHA-1: 6d1a78d5a5e812b59707e5dfdb4995479d82c084 SHA-256: 72c9256510c013b7daad82f8d7c14619c0e0d1aefca3ed4e7bd52e3f31b1bbcf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous external URIs and link farms pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The PDF structure and embedded URLs suggest a phishing lure, likely attempting to trick users into downloading further malicious content or visiting credential harvesting pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://infrive.ru/uplcv?utm_term=no+objection+certificate+pdf PDF link annotation
    • https://chetanaus.org/bheru/uploadfiles/file/56044981093.pdfIn PDF document text
    • https://fl-forever.com/upfiles/editor/files/1129449811.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/vei86lb4bqp1mv9ogl4e07g22f/tezukexaxexaxaz.pdfIn PDF document text
    • http://geredekombiservisi.com/userfiles/file/15027770967.pdfIn PDF document text
    • https://krossi.ru/images/content/files/piludipovilisol.pdfIn PDF document text
    • https://10glazsikeyrosa.ru/file/veluxafas.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609f318ba0b7f---12781248561.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/16103b1fc301d0---nadinud.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ed57de99f4---jipixebizoputitiko.pdfIn PDF document text
    • http://ulrike-mayer.de/userfiles/files/43445395899.pdfIn PDF document text
    • http://dailyliving.nl/ckfinder/userfiles/files/56380637577.pdfIn PDF document text
    • http://adriennemason.com/assets/files/67632613785.pdfIn PDF document text
    • http://vietsinphar.com/uploads/files/36518097370.pdfIn PDF document text
    • https://www.reachcast.ca/wp-content/plugins/super-forms/uploads/php/files/2530cd2ffe4c2dfdb4ac11b508d4b56c/18565480729.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/22721072728.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160ae011c470fd---4336315105.pdfIn PDF document text
    • http://bacvietexpress.com/upload/userfiles/files/garazesamenisurub.pdfIn PDF document text
    • http://toyotarenta.net/FileData/ckfinder/files/20210724_0FBBF8E10574A0F1.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/1611af6a3eec12---67500033198.pdfIn PDF document text
    • https://szallas-karpatalja.net/upload/ravak.pdfIn PDF document text
    • https://cakkue.com/contents//files/saboxanovovafilolubedi.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_off0000bd7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD7A 10648 bytes
SHA-256: a0b3ce4694417aa1a7d5afab2ad7cef96b2119dbee0b784a133636b02e771e01
font_01_sfnt_off0000d5b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5B5 16280 bytes
SHA-256: 9f6b14b60c84e0e8658c79828d008c1f34858659033e2f10ae237a665ff6928f
font_02_sfnt_off0000ff57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF57 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1