Malicious PDF — malware analysis report

Static analysis result for SHA-256 e55fe6499eeca324…

MALICIOUS

PDF

89.2 KB Created: 2021-03-30 12:39:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 66e5c6ba7df1154076f49b0593741e6c SHA-1: f70407fc54140e9475d3bcffaa4e1a34c26751ff SHA-256: e55fe6499eeca324b63ae33a054d670ce010e6687847d575fee5afb9157ab858
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm on disposable hosting, with numerous external URIs pointing to various domains. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDF versions of web pages, further supporting the link farm hypothesis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://resalured.ru/wix?keyword=casos+de+factorizacion+factor+comun PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4402246/normal_5fd3848ec47bd.pdfIn PDF document text
    • https://pixelisikug.weebly.com/uploads/1/3/1/4/131407736/43963991f5c30.pdfIn PDF document text
    • http://rujewazaxijaza.sportsontheweb.net/vaxubifiladesofop.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393208/normal_5fcbac2f402e6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409236/normal_6062dd5193fe0.pdfIn PDF document text
    • https://dolepaxutafajur.weebly.com/uploads/1/3/0/9/130969408/vafanugiv.pdfIn PDF document text
    • https://difidewuwigexej.weebly.com/uploads/1/3/4/6/134652805/totozerux-vozomi-rozegedukafusiv-sotiragalejuz.pdfIn PDF document text
    • https://kisagisetiduke.weebly.com/uploads/1/3/4/7/134762251/josifose.pdfIn PDF document text
    • https://kafijojiwagovi.weebly.com/uploads/1/3/5/3/135387916/gabisal.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://walarerefuzaw.epizy.com/37793394737.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/64289eab-a019-4872-9ad7-80db7a2bd0ae/34366690502.pdfIn PDF document text
    • https://48e4e0df-78ce-4736-8797-27735e68dc67.filesusr.com/ugd/f3b179_b2ec20e8098545c39c8fb71813e061d7.pdf?index=trueIn PDF document text
    • http://raxatimax.rf.gd/euro_truck_simulator_2_cd_key_2020.pdfIn PDF document text
    • http://maretubozewugi.myartsonline.com/sefivunofulowifavebibit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6c98ed09-b01f-4724-8708-d8ab7a8df555/dark_souls_2_dlc_release_order.pdfIn PDF document text
    • https://c63359c4-faa5-40af-ad11-254ddd3d100c.filesusr.com/ugd/838c33_4b35d5837ee54b2eb25aa512281af878.pdf?index=trueIn PDF document text
    • http://nopuwezivobevuk.rf.gd/a_level_environmental_chemistry_notes.pdfIn PDF document text
    • http://kakapefetabol.rf.gd/pleco_chinese_dictionary_for_computer_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/57d78c97-d731-469c-b018-c15002ea3396/jail_time_for_3rd_degree_felony_in_ohio.pdfIn PDF document text
    • http://zorogeloma.epizy.com/fafamavasedorokoraxatewo.pdfIn PDF document text
    • https://6f1239e7-da96-47bf-8adb-22d47a96a9da.filesusr.com/ugd/bb5a15_1e6f80ff54dc4350b25a2e88d261e85a.pdf?index=trueIn 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://scripts.sil.org/OFLIn 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_off00010697.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10697 5088 bytes
SHA-256: 0faf771f643aa8c873a9ff0bae4c019b88309e65d8cc1ad1ca49de50ff6bf73d
font_01_sfnt_off000117d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117D7 12236 bytes
SHA-256: b542e3f778fb250eb4c95918beb5cee7dccbad323f68e8002aa3338b46225fbe
font_02_sfnt_off0001403e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1403E 16060 bytes
SHA-256: ae97ebdbf5cb6679ee3ae7f6f8963da9ec2437ada1f672a33085bc8cbe806833