Malicious PDF — malware analysis report

Static analysis result for SHA-256 f743783e655ba5cc…

MALICIOUS

PDF

101.0 KB Created: 2021-08-02 17:55:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8cd586af20b64736aee873a8875c509a SHA-1: 42231ea4584bebd2ae1b539c90b6657c3277b51d SHA-256: f743783e655ba5cca5d3fd6f2d0ade249b7c725d296fe3bb2149c1201d0653f8
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external URLs, many hosted on compromised WordPress sites or disposable domains, suggesting it functions as a link farm for phishing or malware distribution. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://laborke.ru/uplcv?utm_term=king+kong+hollywood+full+movie+hindi+dubbed+download
    • http://sorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/6837150774.pdf
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160f9d5e5cae4f---14713060125.pdf
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba1fc4a0b79---24156638958.pdf
    • http://call.ae/wp-content/plugins/formcraft/file-upload/server/content/files/1609dd3535993a---57394929747.pdf
    • http://igigeothermal.jp/userfiles/file/74989946740.pdf
    • http://alpanelektrik.com/depo/sayfaresim/file/4495479195.pdf
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16076606213310---69020319093.pdf
    • https://ibeguiristain.com/userfiles/files/73240286035.pdf
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/160764b4fd4ec9---30529277308.pdf
    • http://fine-cottage.ru/userfiles/file/68012994165.pdf
    • https://bistakalikotenetwork.com/userfiles/file/pifagozalepotapeb.pdf
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/o6t4ep35spprr3t7o8kqk5rohk/zafokarenojemov.pdf
    • https://ihotel2b.com/upfiles/editor/files/pixozosoduw.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d6cb050014---69162022567.pdf
    • http://stellamaris.cz/userfiles/66948811049.pdf
    • https://maximatrimony.com/ckfinder/userfiles/files/6240625794.pdf
    • https://dnsbp.com/all4help/fckuserfiles/file/jisinigovemu.pdf
    • http://headlinesdinerla.com/uploads/files/91599000446.pdf
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084b8e39e307---1926861084.pdf
    • https://marjoyunlar.com/calisma2/files/uploads/38374581850.pdf
    • http://majesticcaliberenglishlabradors.com/clients/a/a7/a77fae3751d16767b5fd1969bdae34dd/File/1951451332.pdf
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608fbbd6a0e4f---3930099181.pdf
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/a97ca37fb470e4d289a038cb0864ac75/61110240205.pdf
    • https://alternativecarrepair.com/userfiles/file/16975428194.pdf
    • http://www.santabriganti.org/admin/ckfinder/userfiles/files/75342373077.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010516.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10516 16792 bytes
font_01_sfnt_off00011d28.bin
fee6ec6bbfee48d5e25936fe3e6980961bb67b86d049e50d5fe1e6329c0cb761
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D28 17872 bytes
font_02_sfnt_off00014ba4.bin
b04892693d48579973988a3f3f374105a98ac429cc7f6ed548cd143f3cb0e9d1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14BA4 11024 bytes
font_03_sfnt_off000164da.bin
3ded9aaca2ef9e6c6e95cee9882111b9cda0db582afcb602817e0619031ab472
pdf-font-stream PDF embedded font (sfnt) at offset 0x164DA 18776 bytes