Malicious PDF — malware analysis report

Static analysis result for SHA-256 90f51b575133e214…

MALICIOUS

PDF

76.0 KB Created: 2021-04-06 22:09:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: e979a195b58f2f36502fc7f703159a57 SHA-1: de1147a0e04f0c667db2762e4f4b1583e6ecfd26 SHA-256: 90f51b575133e21416da2f281a4451fdd9ff44766e77350003c4ff416eb81739
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 hosting, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were directly extracted, the PDF structure and embedded URIs are indicative of a phishing or redirection attack, likely initiated via spearphishing attachment.

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://kuzutuzo.ru/strik?utm_term=dake+bible+review PDF link annotation
    • https://cdn.sqhk.co/nepajenine/giKdIVC/meme_template_free_download.pdfIn PDF document text
    • http://carinsusa.info/spectrum_math_workbook_grade_8_free92cvz.pdfIn PDF document text
    • https://cdn.sqhk.co/naxibibu/piagcfP/les_barricades_mystrieuses_piano_sheet.pdfIn PDF document text
    • https://cdn.sqhk.co/padumaxifop/ijjchbL/tidereboxaxixewozun.pdfIn PDF document text
    • http://gromstroy.com/fovokodevopajatezogemigs9rhn.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476925/normal_603dc1825afda.pdfIn PDF document text
    • https://cdn.sqhk.co/vutowogipu/5TggwHj/fomugav.pdfIn PDF document text
    • https://cdn.sqhk.co/podiwilur/IQLjfhe/wodivifukububiriv.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417040/normal_5fe4355ab98c5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490129/normal_6028b4ee8e4d8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367632/normal_602b6a103a56f.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://8ed7b8cb-9bae-4def-ad9b-66b28cd11f91.filesusr.com/ugd/740d8c_ad899b095e9b432a9564f4dabc5b53c3.pdf?index=trueIn PDF document text
    • https://79e8b926-cc52-4cef-90ae-68e3990d752e.filesusr.com/ugd/694d5d_902d62640f4444888d3b2b3a6411ecc4.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/d4151781-dd8b-402f-9320-f33a490851d1/jonoleletisu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4452010f-450b-4b2f-a372-4e78ce8ece58/56302637698.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b851cb9b-b185-428f-b863-fe463bfc4120/first_aid_usmle_step_1_2021_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/355e7ee9-7104-4343-9101-e7c0ed86d581/85196732085.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7676386a-0f4b-46e1-9e2b-de9cbdc229e0/77189713204.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9eb97119-7b56-443e-86bf-f4f9c4429480/39560922551.pdfIn PDF document text
    • https://5849b288-062f-49f8-a71b-da420f1f00fd.filesusr.com/ugd/c068f8_c1be189a931c4508854818153a342667.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/e58c60e6-0cf4-402e-860f-a6162fd4de04/how_to_adjust_schwinn_ic4.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_off0000eb6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB6E 4856 bytes
SHA-256: c634e87683c35d650783c9e0bc42ed6bd0b8f56d2d8ad6e09d4cd4644a37cbd7
font_01_sfnt_off0000fc1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC1E 11500 bytes
SHA-256: 1531e15cf42c9b5f90f91f020c29a60b291de4b7bb0677df1e85321dcbf41531