Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3e9cf636b4d7f27…

MALICIOUS

PDF

69.4 KB Created: 2021-09-28 08:12:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 5fddc1a41e168f77247e7ccd8a82d2c4 SHA-1: dc482178565c4a0955c870b7f20678076b5d6d60 SHA-256: f3e9cf636b4d7f27c3f5cc1adbb7f910b812180658a5c611468491925f7db093
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of embedded URLs pointing to disposable domains, suggesting a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to obscure the true destination by using many distinct, low-reputation hosts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://coretry.ru/uplcv?utm_term=download+quick+boot+app+for+android PDF link annotation
    • http://dabaizhongxue.com/upload_fck/file/2021-9-8/20210908025008522331.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/lanetap.pdfIn PDF document text
    • https://warungmimpishio2.com/contents/files/bivusenixisina.pdfIn PDF document text
    • http://lisaarkinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pejazorilegamaganugo.pdfIn PDF document text
    • http://aolisenjiancai.com/data/files/28398364125.pdfIn PDF document text
    • http://nepodoshlo.kz/ckfinder/userfiles/files/20984961420.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b12f5c90f4---72234481883.pdfIn PDF document text
    • http://gaudi.tw/upload/file/pajarefizapemerozaz.pdfIn PDF document text
    • http://oipipleszno.pl/userfiles/file/fitijofalibibojetu.pdfIn PDF document text
    • http://forumts.com/ckfinder/userfiles/files/92696012928.pdfIn PDF document text
    • http://voijin.com/userfiles/files/vaduwirorulabapovawiko.pdfIn PDF document text
    • https://peoplesmodelinternational.com/ckfinder/userfiles/files/nugokizezuva.pdfIn PDF document text
    • https://nvsrolko.org/ckfinder/userfiles/files/75234915017.pdfIn PDF document text
    • http://thevalleytrader.com/files/12495219214.pdfIn PDF document text
    • https://excore.hu/ckfinder/userfiles/files/10067245245.pdfIn PDF document text
    • http://sxnqx.org/upload/file/Fl202109151920413588.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161338672514e9---92418833493.pdfIn PDF document text
    • http://neoneofitou.com/ckfinder/userfiles/files/30968749034.pdfIn PDF document text
    • https://mokhalasati.com/userfiles/files/pikaribowibepegubuset.pdfIn PDF document text
    • http://ps-chiptuning.hu/userfiles/files/pulurolatekamimo.pdfIn PDF document text
    • https://kinhdoanhvaphapluat.com/img-dn/files/45384927047.pdfIn PDF document text
    • http://nifaelectronics.com/userfiles/file/beduvekafokavezibadizetox.pdfIn PDF document text
    • https://walnutcreekguide.com/wysiwygfiles/file/55038628994.pdfIn PDF document text
    • http://hanlacsclub.com/ckupload/files/wadev.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_off0000b137.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB137 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c94e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC94E 10876 bytes
SHA-256: 2bfb7045c4a30a6b885419f1444f69417fc1eca93e1300d7e2da24ddd15fe538
font_02_sfnt_off0000e21d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE21D 14836 bytes
SHA-256: 46b1031f9a5503dc0808e79f8428ec905952c1611ec27e019d6f75da61e61abe