Malicious PDF — malware analysis report

Static analysis result for SHA-256 8558ea93fc737e6f…

MALICIOUS

PDF

78.7 KB Created: 2021-04-10 21:16:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 4838cb0738a19c46e4a9e45c04935acf SHA-1: 728123d9e244665e5e38438f8eeb01762ba79843 SHA-256: 8558ea93fc737e6f01f9b388f027f3f569e4da3aedd973706a7230d11089f91f
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 0.9997

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://xajibur.ru/strik?utm_term=skyrim+se+graphics+mod+list PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4416304/normal_6035b0d0e38cf.pdfIn PDF document text
    • https://cdn.sqhk.co/vupapevixu/VOWiigf/fashion_beat_game.pdfIn PDF document text
    • https://cdn.sqhk.co/mibupufek/jeiijjJ/karidolosow.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383925/normal_603be065ca6f1.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4379959/normal_5fde550d47bb2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481157/normal_5fdbdd306a2db.pdfIn PDF document text
    • https://cdn.sqhk.co/rarirawibowo/jjiaoge/dragon_world_movie_telugu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366029/normal_6013689ab0961.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://abee6ad4-cf47-459a-954e-22b9b9bb30ad.filesusr.com/ugd/4bdc6d_ef775c7d40684098b3ba8683ab668d4a.pdf?index=trueIn PDF document text
    • https://e85625e8-91d5-48c2-95a4-67b7b95d5b39.filesusr.com/ugd/b97a97_ba162e66fc1646b08015669b32a811ef.pdf?index=trueIn PDF document text
    • https://788ae96d-7a4f-4726-91a9-07bb742fb3e7.filesusr.com/ugd/97aff7_0e10bf043ccd422cbd163b52bd777a2c.pdf?index=trueIn PDF document text
    • https://5b949be5-44ef-49af-96c7-0ebaa8fe632e.filesusr.com/ugd/3402b1_9697a5b34e044c34a16ef2564b853d71.pdf?index=trueIn PDF document text
    • https://6754c94d-8795-460a-880d-d127bb37d4d4.filesusr.com/ugd/2383dc_d2cce77c24f544fd9f20160521de9ec3.pdf?index=trueIn PDF document text
    • https://a3de454e-1598-42bb-a259-4eb69c42f179.filesusr.com/ugd/fb5067_68917236e543487bb842db8450b3bb25.pdf?index=trueIn PDF document text
    • https://8dfdba76-182f-4dc4-9dda-37a8c8d09dc9.filesusr.com/ugd/4ae4db_a196c3deb506451abbf31f7c5377ed6c.pdf?index=trueIn PDF document text
    • https://e9593579-f51f-4dc6-af55-2543ab512b45.filesusr.com/ugd/37952c_bf20c5c8083d4eaa8d56da4fea7839b7.pdf?index=trueIn PDF document text
    • https://67258aaf-84c5-4a88-bfd2-1aa7ddb6c27a.filesusr.com/ugd/850f07_49bcd201dbbf44e4ab1158078b44fc7c.pdf?index=trueIn PDF document text
    • https://98be45bc-63b9-4117-aff7-84a3d4f2c4a0.filesusr.com/ugd/90c678_e225bd1f74f14d848c0b685ec5fdee6f.pdf?index=trueIn PDF document text
    • https://5be7aec3-7d66-433b-ae1d-2bfb807ddf2a.filesusr.com/ugd/24deb6_e5e49e0f654d4346afa4d8079572b7f7.pdf?index=trueIn PDF document text
    • https://0a01f052-6ee6-4bfa-868d-d2e49373b03f.filesusr.com/ugd/55f640_ae9a9802065b424ebf7129ece67767af.pdf?index=trueIn PDF document text
    • https://bed1e925-73f7-457c-87ff-53f226988024.filesusr.com/ugd/d4a8ce_a4ff23a13a1d4cb9a33695a5b58f47b0.pdf?index=trueIn 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_off0000f4d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4D3 5756 bytes
SHA-256: f2d7acfe076cd9f1a8a26852f4954fd0d7ab23ff8f8b9e7218232b4d9c9e3dcb
font_01_sfnt_off0001084d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1084D 10976 bytes
SHA-256: 1a503827f99b11bb095d477c67fac9590708f47d978530fe02f66b66c3e1359f