Malicious PDF — malware analysis report

Static analysis result for SHA-256 4aa55fe2453959dc…

MALICIOUS

PDF

91.9 KB Created: 2021-03-23 12:33:32 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 64b12a27b08473cc0231ff164f5dd4f6 SHA-1: 8722cf078bdc836cda14c4f353cbd0b433328afa SHA-256: 4aa55fe2453959dc6516bf4116d961ee1934a9be4755e3291c3877c9948b67df
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many of which are hosted on disposable domains, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, specifically identified as phishing and potentially a trojan. The embedded URLs and the nature of the link farm point towards an attempt to redirect users to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://vilenefex.ru/123?utm_term=buku+agama+islam+pdf
    • http://kinemulawaw.sportsontheweb.net/miritimemipimupag.pdf
    • http://benaletuzulug.sportsontheweb.net/guia_acuerdo_286_bachillerato_2020.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://80b2a579-f9ed-4aa0-b91a-ac3c8973c086.filesusr.com/ugd/353d00_d0846332c98a46d4894cd31b1ef6f6f1.pdf?index=true
    • https://882e4f53-a7e1-4d4a-89e8-a6e6d9f9b805.filesusr.com/ugd/9a13d2_bbbf1b615e774017896dc92c8c70a61b.pdf?index=true
    • https://e4c06157-4c4c-4c30-848d-1ce07482e123.filesusr.com/ugd/99e070_1e7356f13d91478d98e99b03b103a75e.pdf?index=true
    • https://154530d8-637b-49d0-b90a-43bf07a176fb.filesusr.com/ugd/59359a_a26448e36321463cb17cf60bad765bd6.pdf?index=true
    • http://fosixijikalapi.epizy.com/judeninekesotito.pdf
    • http://sojatuduko.epizy.com/93426817529.pdf
    • https://uploads.strikinglycdn.com/files/0ec1f7ea-49d0-42ee-be86-664cb6e39d1a/the_stand_movie_1994_cast.pdf
    • https://8bd0dbf5-62e0-4684-a95a-1d9666dfa34a.filesusr.com/ugd/e71694_774453d97ef04b3c942556671346f8bc.pdf?index=true
    • http://kubomefewofumim.atwebpages.com/passport_renewal_form_2020.pdf
    • https://uploads.strikinglycdn.com/files/8d4c09b1-bbd0-4430-a925-bdec682b41f5/que_causan_las_celulas_afectadas_del_covid_19_en_nuestro_cuerpo.pdf
    • https://3ae4d138-4ba3-4962-98fb-1b98b40a6a82.filesusr.com/ugd/38062a_33916c797c2a4d26a1833410a8fbf917.pdf?index=true
    • http://newalutu.rf.gd/wedding_checklist_template_excel.pdf
    • https://4eb83289-b313-4542-b68c-79a1d4783db4.filesusr.com/ugd/f6336d_4f3bbb5e373d47ae92061dd869073bbb.pdf?index=true
    • https://uploads.strikinglycdn.com/files/a2df3f44-dbbd-421d-acfa-0f829d9bc93a/ligadajenoserodoselen.pdf
    • https://a12a05ab-6462-4855-b086-b0a2a961d6d8.filesusr.com/ugd/2c76f4_6085a0cb55fa4a6c89d27cefb1300789.pdf?index=true
    • https://35548484-ce42-4b18-9d9d-834326683263.filesusr.com/ugd/a221b6_85151ba724f749e2a51d759016e4fcae.pdf?index=true
    • https://0a01f052-6ee6-4bfa-868d-d2e49373b03f.filesusr.com/ugd/55f640_d74f10ad807343b891230cc2f2f50e19.pdf?index=true
    • https://b1e6e3cd-24a2-426a-8b7d-e8f4bd81915b.filesusr.com/ugd/83e584_d5253240fe304e029530e1e9d8c2fc3c.pdf?index=true
    • https://3bcdeb60-9876-4d14-bc0a-1dd1632c647c.filesusr.com/ugd/16a96a_907d6707681b4a64a6ccf003cba4cb81.pdf?index=true
    • http://wujukigow.rf.gd/nuvepakexewo.pdf
    • https://uploads.strikinglycdn.com/files/3e069426-08d2-4781-b9d1-ee937c76b0e9/what_does_proverbs_30_5_mean.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://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011b63.bin
a9edfca53af094bef455747894060beeeca65ff20a878d3b98b567e7812adaa0
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B63 4848 bytes
font_01_sfnt_off00012beb.bin
7768975e76b3ecd30d62f2888d76db58f94f47de5ec4b9f31f6808d45d799ce3
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BEB 11292 bytes
font_02_sfnt_off00015280.bin
ce7e2e230a41ba6fc2d7d2240890c8289d67876d84a3d076d67c0b48111c8230
pdf-font-stream PDF embedded font (sfnt) at offset 0x15280 4324 bytes