Malicious PDF — malware analysis report

Static analysis result for SHA-256 e35e22a627de6eb7…

MALICIOUS

PDF

74.1 KB Created: 2021-03-29 14:25:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 1ecdc7102a491585ba1c8065be2b478b SHA-1: ebead870b96ada7344870cff48ea597594f17428 SHA-256: e35e22a627de6eb7d8bbeebc7d755b91a3a6da0da3e56c39db951e86f6f12cd8
186 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier. It contains a large number of external links, with a significant portion hosted on disposable domains, indicating a link farm or redirection scheme. One of the primary external links points to 'kuzutuzo.ru', which is likely part of the malicious infrastructure.

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://kuzutuzo.ru/strik?utm_term=how+much+does+a+3+ton+air+conditioner+cost PDF link annotation
    • https://maraliva.weebly.com/uploads/1/3/2/7/132712127/renoveduve-vogoparuxufexub-zanejubobetixov.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388420/normal_604049bfef39e.pdfIn PDF document text
    • https://cdn.sqhk.co/pewowutefiw/cXha9jf/xepevafare.pdfIn PDF document text
    • https://cdn.sqhk.co/moviferu/8yiahsk/vodifusalesagam.pdfIn PDF document text
    • https://jofovumilaj.weebly.com/uploads/1/3/2/6/132681264/zomejugiv-xiluvadiwixixop.pdfIn PDF document text
    • https://xigeworimejol.weebly.com/uploads/1/3/1/4/131483719/pumasogupupedevin.pdfIn PDF document text
    • https://fuzuvetidodevik.weebly.com/uploads/1/3/4/6/134637128/5745849.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415748/normal_5fe75bf7cbe16.pdfIn PDF document text
    • https://vebuleme.weebly.com/uploads/1/3/4/3/134321641/3b3a02.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/3afe6917-4e00-4e6b-bb67-7fd6fb1029c4/what_is_the_stanza_of_a_poem.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6c329aa9-eee8-4d9c-99eb-e5840208033e/kidexar.pdfIn PDF document text
    • https://8d67285a-e3c5-4820-bb1a-bb91ce1079a6.filesusr.com/ugd/d54300_d43c58a3d1314b67a02949d8f8c1b577.pdf?index=trueIn PDF document text
    • https://01d7ec8a-e38e-4e33-8c76-1be31754498b.filesusr.com/ugd/24d943_8c304fcc45ac400f9faefa7df711489e.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/nefomojuwet/photography_101_nikon_d3500.pdfIn PDF document text
    • https://6cb1c90e-07cf-4522-b85d-4edd8abc33c8.filesusr.com/ugd/0c41e7_8fb566dccbcc4a2aa367d1ec4dc03780.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/e8c0ba11-dd39-4cd0-b950-d3e4eacd7a8a/how_to_replace_the_belt_on_a_honda_lawn_mower.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/efea4424-aa0f-476a-9e3d-679fba490b5f/49713651752.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/78154a49-a0b2-4729-9d56-e3649e6f0d0a/horseheads_elks_club_fish_fry.pdfIn PDF document text
    • https://s3.amazonaws.com/kuxegu/across_the_board_crossword_answer.pdfIn PDF document text
    • https://s3.amazonaws.com/ziwuvijevo/tp_link_hs200_no_neutral.pdfIn PDF document text
    • https://s3.amazonaws.com/vofadoloves/jinagubapilubo.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_off0000e41b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE41B 5364 bytes
SHA-256: 48cf58a6466fec5b6f4d999b63049dacb3a722a9e4551b14d3da33c658271781
font_01_sfnt_off0000f637.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF637 10308 bytes
SHA-256: 8683ebd282e3610c15ef47d3a966f0bab3dd100a6a31fbde1554fa4f70a44e2b