Malicious PDF — malware analysis report

Static analysis result for SHA-256 dfbd3e1e13df0830…

MALICIOUS

PDF

66.8 KB Created: 2021-06-07 21:16:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 4bb9ecc9906ab7e0dff154860c6a7d95 SHA-1: 010d53d05ba87538ab8f67efb128e6ecd4e31250 SHA-256: dfbd3e1e13df0830d0fbf5e3e5598675edd8fbacbe98de2a458c1f7d074ad56c
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable hosting, and is flagged by heuristics as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO spam or phishing. While no scripts were explicitly extracted, the PDF structure and link farm behavior suggest it's designed to redirect users to malicious or spam content.

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://krisoc.ru/pbw?utm_term=sources+of+law+icivics+quizlet PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4455884/normal_600f5bef7d58f.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4383917/normal_60b257252c24e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484806/normal_5fe9fb87d1bd1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4372696/normal_603ba8000e0ed.pdfIn PDF document text
    • https://rusopanuguxixat.weebly.com/uploads/1/3/4/6/134640346/a2d8dd.pdfIn PDF document text
    • https://jugukibe.weebly.com/uploads/1/3/0/7/130740256/xujudope.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385617/normal_602b585dc0f2b.pdfIn PDF document text
    • https://kivasemav.weebly.com/uploads/1/3/2/6/132680863/4602754.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/5145288b-1fc2-4901-b5ad-5720433f2264/gedobekuwigasiru.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8cf33435-b460-4a07-b616-65ab89e48326/87934797605.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b1cebc5c-59a1-4770-b0c4-2ef226e7bcef/fimidalivewofij.pdfIn PDF document text
    • http://movapog.pbworks.com/f/79421867146.pdfIn PDF document text
    • http://fogofalo.pbworks.com/f/mikaligejux.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5426fc5b-3bdb-4897-b4e2-3c1be8fed0ce/how_to_set_up_xfinity_xr2_remote.pdfIn PDF document text
    • http://jananevava.pbworks.com/w/file/fetch/144809700/ziremod.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7eca7949-10e5-4227-9260-377104cb2b2f/69352699779.pdfIn PDF document text
    • http://mivegaz.pbworks.com/f/como_ganhar_dinheiro_gratis_no_covet_fashion.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f540ff87-dbbd-4172-8e4b-152dad761e75/full_and_final_settlement_letter_format_in_microsoft_word.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1d99ab0a-952e-440b-a7c1-1f0e377cbaf7/nefisawevixesovuwesed.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e26ee317-7217-4473-becb-f35c6a6913da/figure_drawing_design_and_invention_book.pdfIn PDF document text
    • http://gajufabeke.pbworks.com/f/printable_free_scroll_saw_patterns.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5bd81408-ed01-457a-a288-8277a5dbd053/how_to_reset_a_whirlpool_duet_sport_dryer.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_off0000cad1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAD1 5308 bytes
SHA-256: fc437461e7781ec642e01a806055176af969d955cdf20f6b406939ddf20f9070
font_01_sfnt_off0000dd13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD13 9648 bytes
SHA-256: a9c741760e5992b0e4828e5772fe56699f1edd3527a936018f9e052d2f9d1731