Malicious PDF — malware analysis report

Static analysis result for SHA-256 a2281d3839edc3fc…

MALICIOUS

PDF

70.1 KB Created: 2021-05-28 04:30:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: ef6292cc22ae3cf5678311215f50cd0d SHA-1: 5103b3606874c97ba1dbefd49ce30c7637388eff SHA-256: a2281d3839edc3fc34aaffb8473e04423a8af57996eb44976f69817be37e97c4
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and 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 0.9997

Heuristics 6

  • 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 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://baarspo.ru/strik?utm_term=exercices+sur+les+pronoms+personnels+fle PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4368229/normal_606828489d787.pdfIn PDF document text
    • https://selijexobava.weebly.com/uploads/1/3/1/8/131856120/7583724.pdfIn PDF document text
    • https://mokomopepu.weebly.com/uploads/1/3/5/3/135333670/f7fad.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369916/normal_5fc83ade677fd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385613/normal_6048e72f4fe92.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464735/normal_606a81e97910b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410954/normal_60357ea17f67e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388163/normal_6016ebdfb0be2.pdfIn PDF document text
    • https://gekuxufetog.weebly.com/uploads/1/3/1/3/131384115/baxuwevefewasirak.pdfIn PDF document text
    • https://jaserasozupog.weebly.com/uploads/1/3/1/4/131454215/9623890.pdfIn PDF document text
    • https://bokonipazesokut.weebly.com/uploads/1/3/1/3/131398478/pukulodoge_jawiwajin_pomaz_xaloguzamokemo.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/f98f38bd-b172-44ef-8102-3f1200a7315b/padifejajokalilat.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/229ab53c-2dbb-48ed-a27a-faf5d72257e6/82616319416.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/270c0131-dd72-423e-87f6-c37299703a24/logic_puzzles_with_answers_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/28bc4382-8833-4e54-8f98-84c81472864a/17904749712.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3b4b8777-3200-4a1c-8d61-11acdba4a5ed/graphic_design_price_list_2020.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/02034b39-008a-4b1b-88aa-9107a13a4a34/oxido_de_cloro_nomenclatura_sistematica.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/26ce4212-a235-4b0b-ba2c-8e39380a2956/newtonsoft_json_deserialize_c_example.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e2ab193d-33b3-40bd-8eed-b6b47c34062d/alfonso_reyes_echandia_criminologia.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/758c4f48-1f9e-4d72-97ff-dd3bd607abaa/sevosabawijeweluduzora.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_off0000d32f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD32F 4976 bytes
SHA-256: f43fd797df943251638699f211483294cddca705840089da7167d39f3f9ce2a9
font_01_sfnt_off0000e419.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE419 11528 bytes
SHA-256: b7b7e1b984e366e18f221276ee2254a2102a2bf9271a29a182ab6612b658c373