Malicious PDF — malware analysis report

Static analysis result for SHA-256 b55dc3f457034470…

MALICIOUS

PDF

70.6 KB Created: 2021-02-07 10:32:35 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-03
MD5: 54d3959bd5f8ee4fe1e2f10c35de0ad1 SHA-1: 3714492e06de913104c117d58e0a5a6caa4221e9 SHA-256: b55dc3f4570344708bf67d01960b3d756d150305283d741c4232c9c8cda860c2
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified as a link farm. The ML classifier and ClamAV detection strongly indicate maliciousness, with ClamAV specifically flagging it as a phishing trojan. The embedded URLs suggest a phishing or malicious content distribution scheme, likely involving a spearphishing attachment as the initial access vector.

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/123?utm_term=grades+garden+student+login PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4483839/normal_5fd8fb691f5ac.pdfIn PDF document text
    • https://cdn.sqhk.co/zosiwikiw/hfXhe4D/58244276726.pdfIn PDF document text
    • https://sujabowumosof.weebly.com/uploads/1/3/1/3/131398195/fusukugirovi_gavanagasekixux.pdfIn PDF document text
    • http://ilkertr.shop/linda_tuhiwai_smith_decolonizing_met4pk8f.pdfIn PDF document text
    • https://cdn.sqhk.co/baxorurifina/NzDaUie/aapl_earnings_dates_2019.pdfIn PDF document text
    • https://cdn.sqhk.co/wobuwozavenu/iiijiji/doxopuvitoladedifapep.pdfIn PDF document text
    • https://cdn.sqhk.co/zamokaxu/rYXheyP/xorow.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4480745/normal_5ffe715fa62de.pdfIn PDF document text
    • https://fivujage.weebly.com/uploads/1/3/4/3/134316273/84237a.pdfIn PDF document text
    • https://vedalamiru.weebly.com/uploads/1/3/0/7/130776143/7062114.pdfIn PDF document text
    • https://nokajadum.weebly.com/uploads/1/3/4/8/134887388/detuze.pdfIn PDF document text
    • https://mimasalidapu.weebly.com/uploads/1/3/4/4/134466186/lenod_netupuxuruxurin_sidopexulik.pdfIn PDF document text
    • https://bazajiwudimikot.weebly.com/uploads/1/3/4/3/134344454/f55991efc0b7f9.pdfIn PDF document text
    • https://dezazobe.weebly.com/uploads/1/3/4/7/134755526/pivubu_daxose.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4411493/normal_5fcebe75a9578.pdfIn PDF document text
    • http://znakomstva69.space/20568214489qrkee.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000d77f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD77F 5024 bytes
SHA-256: ce8a4ed788b553d65501c6bcf2cda888593846cbbaf6b9b59e8be1057dc75de5
font_01_sfnt_off0000e8a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8A2 10816 bytes
SHA-256: 4bc1d56b8c6c183ff92997f6b3dc1f7e05d8a48b7eccf474e3bf54e918307993

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