Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d7b774425e4a968…

MALICIOUS

PDF

75.6 KB Created: 2021-04-05 04:12:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: cd5a809d42c28f95f9c99908c9381c83 SHA-1: 25e0443d90569fb6732e4ec8b2e9e4ff935bbe04 SHA-256: 8d7b774425e4a9687fe05d7f9e88d7718738bc00e0be5f7b60ea2a8c3b137409
186 Risk Score

Malware Insights

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

This PDF file contains a link farm designed to redirect users to external websites, as indicated by multiple PDF_URI and PDF_SEO_LINK_FARM heuristic firings. The primary malicious URL identified is https://jacksth.ru/strik?utm_term=how+to+fix+ge+stackable+washer, which likely serves as a gateway to further malicious content. The ML classifier and ClamAV detection strongly support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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/strik?utm_term=how+to+fix+ge+stackable+washer PDF link annotation
    • https://mofesifejizovis.weebly.com/uploads/1/3/4/7/134749503/feloboje.pdfIn PDF document text
    • https://podogavefa.weebly.com/uploads/1/3/1/4/131438056/jelogu.pdfIn PDF document text
    • https://jumolemema.weebly.com/uploads/1/3/4/8/134853288/02e051981f640.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/6b60bdcf-3512-4cfe-8a4f-2b85e7d54378/91485826836.pdfIn PDF document text
    • https://s3.amazonaws.com/fonazuzixagizir/is_california_adventure_open_today.pdfIn PDF document text
    • http://kipadijosepo.epizy.com/6800176035.pdfIn PDF document text
    • https://s3.amazonaws.com/sutawowirosuvuv/homo_sacer_series.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4859451d-901f-4947-90ed-6b7ecae7008a/lozasubafomexerigeni.pdfIn PDF document text
    • https://a581e706-3bf6-41fb-8978-ad4d4077590d.filesusr.com/ugd/afbe6b_85753cc212f94fbc9da6025978e94e38.pdf?index=trueIn PDF document text
    • https://ef733714-782c-48ea-8991-1bc0bf0c95f2.filesusr.com/ugd/ad2ade_0e152c33c01e41bf82d2e115d7e91b80.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/25664b94-ee8d-495a-be42-1d70afe21ccc/how_do_you_write_a_short_story_in_one_day.pdfIn PDF document text
    • https://ef5e9b3f-1a8e-4c79-9b60-34b8f8133c96.filesusr.com/ugd/18574e_cdcc5936fea5430aa06922d8fbee35b1.pdf?index=trueIn PDF document text
    • https://33da92c3-26de-4f6b-bf12-1693cb6a6e79.filesusr.com/ugd/0307f2_13c977596c5d42c09ef8687cd84d6ef2.pdf?index=trueIn PDF document text
    • http://zewuvumanoxulo.rf.gd/94095610437.pdfIn PDF document text
    • https://s3.amazonaws.com/nabifovu/javavijek.pdfIn PDF document text
    • http://zarufutebere.epizy.com/nodax.pdfIn PDF document text
    • https://7afcd0b8-98df-42a4-afe0-9544d44c9539.filesusr.com/ugd/74e9cf_eed8067635d94766861c13b4f0eb3fea.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zalomi/troy_bilt_push_mower_oil_filter.pdfIn PDF document text
    • https://94226b1b-8363-4ad6-a779-e61b7b16ff5b.filesusr.com/ugd/b3bc21_00a7c09615274b6ab90bda180878c921.pdf?index=trueIn PDF document text
    • https://ba30dffa-51fe-4caa-9472-6f142403a9bb.filesusr.com/ugd/c2007e_2922d6bde48a4a03916274a74c81374d.pdf?index=trueIn PDF document text
    • http://fubixedogiji.epizy.com/49232629916.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/141418de-2f82-437f-b1a8-9082598eac8e/how_he_loves_us_letra_en_espaol.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_off0000e8a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8A8 5468 bytes
SHA-256: 33c581ad98ea5cd6ea25733e3b9115bbdc7250f254d2056c285cd406cd85f07c
font_01_sfnt_off0000fb5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB5D 11276 bytes
SHA-256: 668e400d7bb2f90907a02773ee43f8eb0f6e7acbac40ca48630f7d2c944c21e7