Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f31701d2a1245b5…

MALICIOUS

PDF

84.6 KB Created: 2021-03-07 20:10:06 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: e8d18a49e69c4a3026bb1c2e4778f83e SHA-1: 1187b11084ecce09f7bebe98285d106be1beb6a2 SHA-256: 3f31701d2a1245b549babbbf32f5f62b273884c99f39e8346fcdb37a72bb7b3b
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable domains, indicating a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to distribute further malware or phishing content. No scripts were extracted, but the embedded URLs are the primary indicators of compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://botokaw.ru/strik?utm_term=what+is+exploratory+play+in+early+years PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4426960/normal_5fed25dfcba1c.pdfIn PDF document text
    • https://cdn.sqhk.co/senosekagoko/0t51n05/digicel_top_up_app_free_download.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495843/normal_5fd63d013c141.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4421042/normal_5fdd5c6d398dd.pdfIn PDF document text
    • https://cdn.sqhk.co/zugivakizo/7pNihia/59254399218.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4428039/normal_5fc6c089e5fbe.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382412/normal_5fdc89bba6b7d.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/20f358f2-7dad-42f6-b61a-dae5c564acaf/what_is_corporate_law_in_canada.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/820ede85-5c4d-42fb-9e0f-39991a42f366/maxadase.pdfIn PDF document text
    • https://s3.amazonaws.com/xisefowu/19762669891.pdfIn PDF document text
    • https://s3.amazonaws.com/gopifu/background_eraser_apk.pdfIn PDF document text
    • https://d80868e2-5d34-4dda-9345-0396294a35aa.filesusr.com/ugd/f9fac6_fde30895c4e143ec99ca7e251eae1de1.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/00e37e9d-e50d-44d7-864d-9082e759fd9b/will_there_be_an_i_robot_2.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ca641493-4c7f-4ce2-a8bd-864ebc007cf0/12028621962.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5dbbd36f-5044-4097-a418-f8b163a88600/python_for_data_analysis_example_files.pdfIn PDF document text
    • https://s3.amazonaws.com/xamibebulosaxug/maple_leaf_ragtime_sheet.pdfIn PDF document text
    • https://s3.amazonaws.com/jojitagifuva/dixiw.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/24e002d5-ca91-4bc9-adc6-93fab39afea0/how_to_write_a_sandwich_paragraph.pdfIn PDF document text
    • https://459ec6dd-5b69-4322-a182-74abbfaa0e48.filesusr.com/ugd/221eaa_cda2b7b5efef465abed1f5e7f9e74e77.pdf?index=trueIn PDF document text
    • https://1c8fadd7-09eb-4d2b-9d42-8e747ba5ce52.filesusr.com/ugd/60625b_8f3f2e45b1dd48c4a8d0bb2a42314ce6.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/70be3d67-1216-4c73-b1ec-bdbec68b021b/merchant_of_venice_act_5_scene_1_solved_textbook.pdfIn PDF document text
    • https://7f03322d-63d6-449b-a8c2-a80beffeb2b6.filesusr.com/ugd/2994dd_f9d8bce9cbb0485aa864b1a90f192841.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/naxizugenabi/drama_korea_cambrian_period_sub_indo.pdfIn PDF document text
    • https://58eafb2e-ea74-4523-a1b2-d2e0fe9bfe54.filesusr.com/ugd/466fa0_7e2a615c0e574e529453d74e16d68213.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_off0000fafa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAFA 5092 bytes
SHA-256: c55753ede55432cb578ce1cb0efe5a5875e9f12bc5d6b70909328c3e37ee3bdd
font_01_sfnt_off00010c5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C5C 10232 bytes
SHA-256: f667f32879c661cdae1864e3841d54d7561c4c1342cfc5cf0bcccd6da2c21a18
font_02_sfnt_off00012fb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FB3 16096 bytes
SHA-256: 292b67320f20e7e38814323bff47001ccb55b5eebb397aea8a254f3e91f57b87