Malicious PDF — malware analysis report

Static analysis result for SHA-256 feef0e7491e09a07…

MALICIOUS

PDF

73.9 KB Created: 2021-06-04 15:20:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: e0e5ebc59c7afad669cd56f58cff6ceb SHA-1: 223750fb1c061ff89ce494a4e4da1c2f3021b3f0 SHA-256: feef0e7491e09a07652bff26c2b4356b51ae9ed312097d3a6ea8cf99cccd2e1e
126 Risk Score

Malware Insights

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

This PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO manipulation tactic. The ML classifier strongly flagged this PDF as malicious. The embedded document body text, though partially corrupted, suggests a lure related to mathematical formulas, which is likely a pretext to direct users to these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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://chcial.ru/pbw?utm_term=productos+notables+formulas-trinomio+al+cubo PDF link annotation
    • https://lepepapiminokuj.weebly.com/uploads/1/3/4/4/134493398/dofabubonesijof_fejubevilasason_rosaru_luxasum.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371267/normal_601120e63fb61.pdfIn PDF document text
    • https://xefufisemir.weebly.com/uploads/1/3/5/3/135393588/c5c1a379d0e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417213/normal_6015dbc25925f.pdfIn PDF document text
    • https://roluliduz.weebly.com/uploads/1/3/4/7/134771057/6192771.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4476002/normal_60000567b4359.pdfIn PDF document text
    • https://ribavazo.weebly.com/uploads/1/3/5/3/135322422/d6299cd90c02.pdfIn PDF document text
    • https://jafobepajimo.weebly.com/uploads/1/3/4/8/134881918/4097279.pdfIn PDF document text
    • https://bitojobuf.weebly.com/uploads/1/3/4/8/134892495/a0fe15e4011fcd5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4482863/normal_600f1c91a5f97.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481985/normal_600172301b06b.pdfIn PDF document text
    • https://tenifapinam.weebly.com/uploads/1/3/4/7/134711228/rinivawavozigolage.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4477379/normal_5fdcc1e5ace3f.pdfIn PDF document text
    • https://wolapegod.weebly.com/uploads/1/3/0/7/130776073/6027d7.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/2882add6-06b3-4cdf-b875-3ea111e86ff8/how_many_carbs_are_in_a_chick_fil_a_sandwich_without_the_bun.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7d6c927c-7d55-4a78-bf4c-2be3f3f6558b/1572861945.pdfIn PDF document text
    • http://vakerul.pbworks.com/w/file/fetch/144562200/49655820590.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/32181c18-eb65-4ec3-87bd-7f3ca91fa0dd/14925902857.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/26ba900c-5133-4c40-ad91-386d49d9d8a0/34551155023.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d9dd9450-8172-440a-9146-f71a4bc86bc4/87929256730.pdfIn PDF document text
    • http://letonepamusi.pbworks.com/w/file/fetch/144465594/zaxopijedejid.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d3d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3D6 5220 bytes
SHA-256: 23829bcc0951812075ec2a9a297dc9df64e4e969cf1c03b2de49157c7ae42861
font_01_sfnt_off0000e579.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE579 11620 bytes
SHA-256: a5053137b7a94fa4450b2a72e0ff6852e2329e707df8c26dbb2acc6fbb176154
font_02_sfnt_off00010b9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B9D 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c