Malicious PDF — malware analysis report

Static analysis result for SHA-256 8dce28dbaf805b30…

MALICIOUS

PDF

98.9 KB Created: 2021-04-22 13:26:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 955f41d376655abeab905df3b70db87a SHA-1: e0d82e24a3bbe47e47ab3eecb34604396264bf3d SHA-256: 8dce28dbaf805b30e90c9712d7e5adc3f82aee8a2f3dda7278881e0317e80456
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of embedded links, many of which point to external PDF files, indicating a link farm. One of these links is identified as a known malicious redirector, suggesting an attempt to lead the user to malicious content. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://crophysi.ru/strik?utm_term=define+graphic+novels In PDF document text
    • https://static.s123-cdn-static.com/uploads/4494451/normal_5fcc474e535ee.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4499984/normal_60245f73aa0a9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369168/normal_6000164f6df2a.pdfIn PDF document text
    • https://zomafada.weebly.com/uploads/1/3/4/7/134772300/nilemipebuxidiw_temoge_lawizebu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371495/normal_605d879b66186.pdfIn PDF document text
    • http://wojisub.mypressonline.com/m44_bus_timetable.pdfIn PDF document text
    • https://jeruxonoja.weebly.com/uploads/1/3/1/4/131407493/29b3bd4438.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4494674/normal_5fdb74bd86175.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366000/normal_6040ae204a6a0.pdfIn PDF document text
    • http://nokasosozigof.mypressonline.com/ignou_assignment_front_page_2020_19.pdfIn PDF document text
    • https://xabisipejerifo.weebly.com/uploads/1/3/4/6/134634854/8ac4bc3a7f5cd.pdfIn PDF document text
    • https://zalajugimawif.weebly.com/uploads/1/3/0/7/130739284/9817a09db1f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4455883/normal_6027f7cbd9abe.pdfIn PDF document text
    • http://wotukujis.sportsontheweb.net/5035947293.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4473645/normal_6051dd9b70308.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/jeromopelurab/biriwajetol.pdfIn PDF document text
    • https://s3.amazonaws.com/vuzufexarevima/power_air_fryer_oven_cookbook.pdfIn PDF document text
    • https://s3.amazonaws.com/tokafanawa/kojogoriwedefemajufox.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/875b0b12-ef39-4142-8281-4accde4067e1/41213109150.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2c0b4b40-3d62-45f0-b89e-6a6a378423a7/kusifapevijiwalarolot.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cd91a0df-9eae-45ac-bfda-d53a73ca07cf/best_digital_tire_pressure_gauge_bike.pdfIn PDF document text
    • https://s3.amazonaws.com/rijaliwiguvex/how_to_reset_maintenance_light_on_2015_prius_v.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_off00014447.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14447 5336 bytes
SHA-256: 4f99f3a15ddd4b32bfafb241aff5283b979bcf012e19aca920a1bb33e70ff06a
font_01_sfnt_off00015681.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15681 12324 bytes
SHA-256: d871a29f4e77739a930dad46e75c48d06013ac2c8a1ccdd910d7424f1b217ed0