Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a7cc1be21bbd6ee…

MALICIOUS

PDF

78.6 KB Created: 2021-03-14 19:31:27 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 9e5f0525f6791a2505b4fe5c22f7a3f0 SHA-1: 235dada647cdbec6a7e5b5ed8d82cb02e5e6000e SHA-256: 5a7cc1be21bbd6eeca902bb7d0d588d44eadc6aa0d7a700d301ede45994ed947
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://jacksth.ru/wix?keyword=huckleberry+finn+worksheet+answers PDF link annotation
    • http://rubka.space/wuwofevulitakamevenac0147.pdfIn PDF document text
    • http://olx-delivery.cc/how_to_draw_a_realistic_human_eye_step_by_step_easy3or5w.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368758/normal_5fd0a16b6d898.pdfIn PDF document text
    • http://alternativeinfluencenetwork.net/who_is_playing_in_after_we_collidedlvyyw.pdfIn PDF document text
    • http://esclick.pro/bexosuwugibifu7ra64.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4500895/normal_602d4ccac28e7.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/wupixufekijax/how_to_install_electrical_switch_for_garbage_disposal.pdfIn PDF document text
    • https://1c684d3d-b1aa-4d58-8f8e-408f9cf37fac.filesusr.com/ugd/64d889_a30b529867ad41569d8abfe092f6766c.pdf?index=trueIn PDF document text
    • https://6448a590-b571-4b71-a9e4-820b8531b153.filesusr.com/ugd/782be2_97e03760b6fe42619540a10778459b74.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/nufidibodudulad/study_leave_approval_format.pdfIn PDF document text
    • https://ffb80149-315c-4936-8637-e87477b606fc.filesusr.com/ugd/e7410d_08f2c31fd0ba4364affe429c9c211be5.pdf?index=trueIn PDF document text
    • https://f1e11ea9-a931-46ad-af30-391325c877dd.filesusr.com/ugd/423518_8ee66f40ef7045b2a2e9af120129a502.pdf?index=trueIn PDF document text
    • https://a5fc3680-5c08-4cda-bd6c-abaa3bdf25bc.filesusr.com/ugd/ea5d7b_b93888c4f4e4403abb57964067f5eced.pdf?index=trueIn PDF document text
    • https://61069a5e-3c5f-4884-a3c7-8c7552058b74.filesusr.com/ugd/0789d5_9ff9bbc795d14da188c52feaea218154.pdf?index=trueIn PDF document text
    • https://fecd0c08-032d-4b8b-b26c-6108aca7a00f.filesusr.com/ugd/a87c8b_02c9ebf57d614a6e909cb0411183b928.pdf?index=trueIn PDF document text
    • https://8ecf7690-1f99-4e28-a4b6-3228ba9731d7.filesusr.com/ugd/63d3ad_e501191bb39e43b48338365cde37da59.pdf?index=trueIn PDF document text
    • https://5c3e38fa-bf2d-4cda-bfdc-19e9a39f2227.filesusr.com/ugd/b3ada4_f33e90f4f65e490f81b0534e32c1db30.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xakajoziwibi/jekefega.pdfIn PDF document text
    • https://da89e6ec-52f9-4c28-8de8-447a2e923c0c.filesusr.com/ugd/5e5b2a_24caccdc760e4db1b29ec5af292bb9d8.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/fidefofudi/62116191633.pdfIn PDF document text
    • https://d9226533-59f4-4737-ae77-cfa9cdee5378.filesusr.com/ugd/d7c203_416ab1fc7c6d4b5cb5c5683b8df494d6.pdf?index=trueIn PDF document text
    • https://d2faa26e-66ca-44cd-8f84-883624a71019.filesusr.com/ugd/dbbfd0_813dbb4df7c9416f8bad694b4b1acedb.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f68a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF68A 5328 bytes
SHA-256: 3758c780ce0983d31f61700b36d41c48e7246b0c2dcaa1b1a2b87b6089f49241
font_01_sfnt_off000108c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108C1 10620 bytes
SHA-256: 792320e4046b5bce2c202f543f45f359623143853e637660b7ebc1cf11afd59c