Malicious PDF — malware analysis report

Static analysis result for SHA-256 b738037e4c9d6855…

MALICIOUS

PDF

70.4 KB Created: 2021-06-12 00:32:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 39c1b16dffcd2856cfd8ec3382c4f11a SHA-1: 8cc45e872a477539bd1d71ede070808fc0ca0b49 SHA-256: b738037e4c9d6855d2e4b157d9afa72b42a38323f8e1964d80431b77aae14138
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 0.9993

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://medvor.ru/pbw?utm_term=safari+for+android+phone PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4392857/normal_60c3d2d729d60.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488574/normal_605314b0da089.pdfIn PDF document text
    • https://pamumigupoxip.weebly.com/uploads/1/3/4/6/134614169/9022820.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4420927/normal_60b32ec7c21d3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4456663/normal_604cdf8900ac8.pdfIn PDF document text
    • https://dodevapamoj.weebly.com/uploads/1/3/4/3/134352329/nedodometaparigu.pdfIn PDF document text
    • https://tusuwijajibu.weebly.com/uploads/1/3/4/5/134517525/8591622.pdfIn PDF document text
    • https://wadazujirala.weebly.com/uploads/1/3/4/5/134596454/takuxerot.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379722/normal_5fd0f7f116049.pdfIn PDF document text
    • https://tojoxiwumo.weebly.com/uploads/1/3/4/3/134319360/sapejopafidelagufus.pdfIn PDF document text
    • https://silavetej.weebly.com/uploads/1/3/5/3/135314504/9b20c46a.pdfIn PDF document text
    • https://jozevupipe.weebly.com/uploads/1/3/5/3/135346753/vumilazekifukadaki.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/628e362c-277d-4456-8425-4c7bc07a2cef/55581929032.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2735a68f-a9aa-41bb-be41-3926397f159f/86131210841.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/13f834fe-5491-4956-a5cf-d4ff422acad8/raxozojifevizutowaj.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3108ab6e-fc4d-4412-b8de-6ddc75eeeadb/2403486767.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/17f125f6-6337-4745-80dd-fa6a22b9a633/what_is_a_word_that_starts_with_os.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/87237a96-58a2-414d-96ac-4271bb6de881/latilikaroles.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/723b23a1-bda2-41b5-afac-5180efe60e30/8080772731.pdfIn PDF document text
    • http://gabumur.pbworks.com/w/file/fetch/144657198/mslm_grses_filmi_indir_mp4.pdfIn PDF document text
    • http://sajateves.pbworks.com/f/bagawemipapik.pdfIn PDF document text
    • http://jadubunid.pbworks.com/f/google_sheets_travel_expenses.pdfIn PDF document text
    • http://najajufuf.pbworks.com/w/file/fetch/144948774/26909555432.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_off0000d85a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD85A 5024 bytes
SHA-256: 848e3b8743443e2b729a0c1a6c932087baf4fc179d3cbfd4ddbf88d9f7d9e70c
font_01_sfnt_off0000e96d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE96D 10424 bytes
SHA-256: e50bb225c2794beb32742ac46432d9a1f66cff580b906214edb33388f26a7e1b