Malicious PDF — malware analysis report

Static analysis result for SHA-256 da839783463828d6…

MALICIOUS

PDF

88.3 KB Created: 2021-06-06 08:48:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: db0869d7143d51e0640b43145e753a61 SHA-1: 243643c3388366f041f933cd074182998e449fce SHA-256: da839783463828d610cef27d96b9ae50f9fc9d65dbf1cba89dd4a36ffaa2c64c
166 Risk Score

Malware Insights

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

The PDF document contains a link farm of 30 external links, many pointing to disposable hosting, with the primary URL being `https://queure.ru/pbw?utm_term=kingroot+4.5+0+apk`. This heuristic, combined with the 'Password-protected archive handoff' finding, suggests the document is designed to trick users into downloading a password-protected payload, likely to evade initial security scans. The ML classifier strongly supports the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • 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.
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://queure.ru/pbw?utm_term=kingroot+4.5+0+apk PDF link annotation
    • https://wezawemexa.weebly.com/uploads/1/3/1/4/131410399/jupisozujevu-wimetet-vulukunigo-vamegaj.pdfIn PDF document text
    • https://gozisali.weebly.com/uploads/1/3/4/6/134670052/dec6f95e.pdfIn PDF document text
    • https://nejaxadutoxukax.weebly.com/uploads/1/3/4/6/134622523/5305364.pdfIn PDF document text
    • https://zoxobafibo.weebly.com/uploads/1/3/4/2/134235835/rabivoxu.pdfIn PDF document text
    • https://mezepobavufu.weebly.com/uploads/1/3/4/7/134717124/4979130.pdfIn PDF document text
    • https://rasisepuwefu.weebly.com/uploads/1/3/4/6/134678142/mininuva.pdfIn PDF document text
    • https://xuzojawuwakobo.weebly.com/uploads/1/3/4/3/134312069/2131085.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/b98067af-2bf3-4d0b-a4a1-304a3d2331fa/do_you_feel_what_i_feel_christmas_song.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/18e10699-badc-4e60-8420-41033736ecb3/tl-wr841n_password_change.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9a067473-1c78-4d64-bdb6-bc76c7db9e03/revue_technique_bmw_k75_gratuit.pdfIn PDF document text
    • http://subazim.pbworks.com/w/file/fetch/144683343/cuanto_pies_es_un_metro_cuadrado.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4f95ce99-ec4e-4aae-8567-1b5bea6dc291/turigomeguv.pdfIn PDF document text
    • http://litorabi.pbworks.com/w/file/fetch/144485586/75399195360.pdfIn PDF document text
    • http://jejosuxiz.pbworks.com/f/galufurilesibuzixamim.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e92d2875-7b2a-454f-8d60-9e2802fd5e3f/database_systems_design_implementation_and_management_10th_edition_answer_key.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/de3655b0-f9fe-46ad-906e-0c7293c9da31/communication_skills_meaning_in_urdu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/151156b4-9190-4b4f-b96b-1e493945451d/how_to_use_apple_time_capsule_for_backup_only.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f512435a-1726-4877-82a1-8f4342e57091/xifapejozumi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ca8117ea-c102-409b-9a1d-e2304878b7f1/electric_pallet_jack_user_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/04c56807-49ec-4ca2-bfd4-043c2f4b13e7/99626235736.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off0001225b.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1225B 28120 bytes
SHA-256: f6ff71142624a8b3f8c1629b9e02203966cdb86548dc853cb387ab0bbdbc0706
font_00_sfnt_off0000ec1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC1F 5196 bytes
SHA-256: 69849cb19a3509f8ad5136e1822a4823faa06257a2ccb56f4c8a65141a9ded5e
font_01_sfnt_off0000fdf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDF4 10584 bytes
SHA-256: 655be0f97252cf376913b2dff21b17c044c122cf49b7d47c1e851221bd820664

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