Malicious PDF — malware analysis report

Static analysis result for SHA-256 c57c3f188a511c2c…

MALICIOUS

PDF

77.1 KB Created: 2021-04-08 09:28:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 084f398be179b804094329fd3820df72 SHA-1: 99240510b881380cf1d4be60811178bc8ec4f519 SHA-256: c57c3f188a511c2cfdf14b062e31edb4f231ff271297194ab7d14b7b82bb35ed
186 Risk Score

Malware Insights

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

This PDF document exhibits characteristics of a link farm, containing numerous external URIs, many of which point to disposable hosting. The primary URL, 'https://jottigo.ru/123?utm_term=math+worksheets+grade+7+square+roots', suggests a lure related to educational content to entice users to click. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • 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 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.
  • 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://jottigo.ru/123?utm_term=math+worksheets+grade+7+square+roots PDF link annotation
    • https://wisolowiguwo.weebly.com/uploads/1/3/4/6/134630140/rosib.pdfIn PDF document text
    • https://vabuxijipureg.weebly.com/uploads/1/3/4/4/134476882/4de5f16.pdfIn PDF document text
    • https://xogudefimo.weebly.com/uploads/1/3/0/7/130775634/jisuxifujis-natajakajesa.pdfIn PDF document text
    • https://gipenozup.weebly.com/uploads/1/3/1/0/131070487/6487581.pdfIn PDF document text
    • https://joxunirefebemi.weebly.com/uploads/1/3/4/3/134319414/pavafata-gokixoxe-nopigajofawok.pdfIn PDF document text
    • https://zeruposizagaki.weebly.com/uploads/1/3/4/8/134854722/5252143.pdfIn PDF document text
    • https://dafelubuvotaxid.weebly.com/uploads/1/3/4/7/134753950/bosezilatexulasofa.pdfIn PDF document text
    • https://kegegofelev.weebly.com/uploads/1/3/2/6/132681159/biwugezenituvotu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/edd69df8-0d19-4cfe-8527-174560bece91/61609527541.pdfIn PDF document text
    • http://wifudozakiteg.epizy.com/sapekepi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2557559a-dbb5-47e0-bd97-b9df1dfba24e/symposium_plato.pdfIn PDF document text
    • http://zunebitalubale.rf.gd/33691864488.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6381ea4e-5103-4cdf-a592-4efe92670f10/42437495549.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/61bc4c63-cbae-4469-9754-605b97da5184/how_to_clean_holmes_humidifier_filter.pdfIn PDF document text
    • http://zuvemodu.rf.gd/california_rental_application_form.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3594a654-d3b2-4577-99e5-c44d72623d70/what_items_do_i_need_to_sell_my_car_with_a_roadworthy.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/202fe3a5-6ec8-483a-97c6-4f3fe7d46493/disadvantages_of_student_database_management_system.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dad4bac2-3dad-401f-a327-8a0294270bdc/62034486259.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ba369105-ba7e-4102-8cea-38e3256d1c4d/wajofoturip.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/78659015-c0b3-4c58-8859-b56bdfb6daae/python_set_add_vs_list_append.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9fbea5fd-f0b8-43a8-b4e8-b81709cfa6f6/63555037553.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000efa7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA7 5424 bytes
SHA-256: 06739c9a84376a409e02a88bf8e21b1aa78547bead1e7728d84870d3443e6f1d
font_01_sfnt_off0001022e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1022E 10712 bytes
SHA-256: 67eab9a8aa56bf78210367beeaf6c3224e2bf3ffa28365f79a2c8a5529553ed7