Malicious PDF — malware analysis report

Static analysis result for SHA-256 16b4f3f9295d024b…

MALICIOUS

PDF

73.7 KB Created: 2021-05-31 03:25:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 7f7512961d976bd2394d913c69f1407f SHA-1: 4562a289d673c3567bf5c831afdfcfee6ec63e1b SHA-256: 16b4f3f9295d024bc21e450b292cac759ec49def370b6653d8240202ba4bcac2
156 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to potentially malicious domains, as indicated by the PDF_SEO_LINK_FARM heuristic. The ML classifier and ClamAV also flagged this file as malicious, specifically as a phishing trojan. The embedded URLs suggest an attempt to redirect users to external sites for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://crophysi.ru/strik?utm_term=libros+de+preescolar+santillana
    • https://cdn-cms.f-static.net/uploads/4413842/normal_5fd17c82e3f3c.pdf
    • https://fudidokogi.weebly.com/uploads/1/3/4/6/134603759/db83d43a9da.pdf
    • https://lisokafi.weebly.com/uploads/1/3/4/6/134694643/zulefelof.pdf
    • https://static.s123-cdn-static.com/uploads/4405419/normal_5ff0dd021e05b.pdf
    • https://cdn-cms.f-static.net/uploads/4393762/normal_603efbf6a6fd9.pdf
    • https://kirebokiva.weebly.com/uploads/1/3/4/6/134634247/3842400.pdf
    • https://static.s123-cdn-static.com/uploads/4375207/normal_6002635684151.pdf
    • https://static.s123-cdn-static.com/uploads/4487191/normal_5fccdb0811a5a.pdf
    • https://xofeboje.weebly.com/uploads/1/3/4/5/134584890/5672698.pdf
    • https://cdn-cms.f-static.net/uploads/4408001/normal_60385632068bb.pdf
    • https://totidulabi.weebly.com/uploads/1/3/1/6/131606487/a191eb09a90d05.pdf
    • https://tuxenovizomojow.weebly.com/uploads/1/3/7/5/137516496/lolag.pdf
    • https://cdn-cms.f-static.net/uploads/4473415/normal_603a05a423a30.pdf
    • https://cdn-cms.f-static.net/uploads/4375521/normal_603322ff44faa.pdf
    • https://cdn-cms.f-static.net/uploads/4460706/normal_606a50fa371c0.pdf
    • https://static.s123-cdn-static-d.com/uploads/4469630/normal_60b109cdf0f5a.pdf
    • https://raromimuzu.weebly.com/uploads/1/3/0/8/130874361/ba0ff396a74fee1.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://uploads.strikinglycdn.com/files/3030ad2f-340b-46b0-9f0f-1c4cb9f76be3/rusofow.pdf
    • https://uploads.strikinglycdn.com/files/fb7ca3b7-e742-4c08-8391-36968fcb2166/char_broil_infrared_cooker_recipes.pdf
    • https://uploads.strikinglycdn.com/files/26d3c247-6380-4503-aaee-2437c4a81a11/80531698858.pdf
    • https://uploads.strikinglycdn.com/files/b1a9b13a-6dad-4bb0-8c07-f27e411b1a79/what_are_molecular_structures_called.pdf
    • https://uploads.strikinglycdn.com/files/d2b93f6d-67ec-4130-818b-cbd84bce427b/health_o_meter_connected_digital_scale_reviews.pdf
    • https://uploads.strikinglycdn.com/files/b20b017d-e13c-4efb-8999-27ea856f4500/how_to_make_a_sticker_on_paint_3d.pdf
    • https://uploads.strikinglycdn.com/files/6d17d1fd-029c-47fd-b7f7-cb087b0ed42b/18615581054.pdf
    • https://uploads.strikinglycdn.com/files/2c4faf5f-8a17-499b-9b21-57173c8f648e/18337225252.pdf
    • https://uploads.strikinglycdn.com/files/b26d28e9-b86a-4de1-bb60-e50ba8270bc4/98479306549.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_off0000d6bb.bin
3abfc96f3545eb7e9f7116bbd002504231b9efa26cf4543f0454d4475e22cac6
pdf-font-stream PDF embedded font (sfnt) at offset 0xD6BB 4936 bytes
font_01_sfnt_off0000e778.bin
5628fb9a8bca2c850ccd28d3a067534315d49a4db7473dbdc64058702d6b441b
pdf-font-stream PDF embedded font (sfnt) at offset 0xE778 10960 bytes
font_02_sfnt_off00010b1f.bin
7f6049e5011acf0e8581793f2bc2bb947aac2929fdb77abc318b2a6155c1ef71
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B1F 4324 bytes