Malicious PDF — malware analysis report

Static analysis result for SHA-256 1bb187c16a98c38c…

MALICIOUS

PDF

80.3 KB Created: 2021-05-29 19:58:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: 822987cb2f34cfec1cde1b6d4aa20e58 SHA-1: 58a38a72003ba38a14cbea64d2363fe7e6555d59 SHA-256: 1bb187c16a98c38cb3b2e5835003d6145c75072b283b87cd736ac6241b1bc3d6
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 5

  • 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://druttle.ru/123?utm_term=english+listening+beginner PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4404488/normal_6014acf27f1c7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481667/normal_5ff9438437604.pdfIn PDF document text
    • https://kotobewel.weebly.com/uploads/1/3/7/5/137500947/f2e77.pdfIn PDF document text
    • https://jomijumad.weebly.com/uploads/1/3/0/9/130970003/napaxitasoxomadavenu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449776/normal_6009e69567ea7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415525/normal_6015d0935682c.pdfIn PDF document text
    • https://mowolonob.weebly.com/uploads/1/3/4/8/134874237/736f878ec3b5ef.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495264/normal_600a724c3741c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459805/normal_6036a236f0aa9.pdfIn PDF document text
    • https://bofufawikifof.weebly.com/uploads/1/3/4/2/134235483/4f401a6d3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4502248/normal_5feb84e6f0aa2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366017/normal_60151ccd1c727.pdfIn PDF document text
    • https://nakakikixug.weebly.com/uploads/1/3/4/4/134490848/zatipur.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465938/normal_5fde9d930c378.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408719/normal_604deb5a31c52.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393193/normal_602115ab23b99.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/a7bd1aa2-e4c5-465e-beba-6a8dec0d7f8e/teaching_emotional_regulation_skills_dbt.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a49bf232-1019-4eaa-9edc-da5acc635f96/what_is_karst_topography_named_from.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/152c299a-aaea-488d-9b74-4b03abba6dc5/breve_resumen_del_libro_el_secreto_del_hombre_muerto.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9b6dd98e-d6b9-42e5-aede-16bbd6d3dfc5/nejebituzebilakeliz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/39150d44-1ed2-4040-bb28-8cc1db92c51d/abilene_ks_warrant_search.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6bd3ca1d-b717-44fb-8bb8-e6b203ec1a5f/what_food_and_drink_is_good_for_period_cramps.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5f1cc682-0e74-47f6-ba35-17adf5f963c9/majeju.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b4f82d32-0a32-4344-bfe0-36074784e661/duo_therm_comfort_control_thermostat_4_button_manual.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f23d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF23D 4512 bytes
SHA-256: 2ec8c22980533e55398bd3a69102d1002c40786a933823ede19f84b5460d7f8b
font_01_sfnt_off0001017b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1017B 10640 bytes
SHA-256: 89d84b3fa4aa5ca71927ea62689bd3a6f9515867b25cebcaa90abef6a9e370dd
font_02_sfnt_off000125b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125B9 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2