Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f56ca4009a9f11d…

MALICIOUS

PDF

83.0 KB Created: 2021-02-26 06:09:46 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: a4f12e15915aac6e1730d54e091e5a0e SHA-1: ae4724f689f5d174c74f11e6fdb106da271b96ec SHA-256: 3f56ca4009a9f11d627e87b7ce47c5f7322c6f4d4172bd0013f4fd7773b21bf7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO spam operation. The document body, though heavily obfuscated, appears to be related to writing a novel, which is likely a lure to disguise the malicious intent. The ML classifier strongly indicates maliciousness, and the presence of numerous external URIs points towards a tactic of redirecting users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://maypoin.ru/123?utm_term=how+to+write+a+description+of+your+novel PDF link annotation
    • https://kawifapexevudo.weebly.com/uploads/1/3/4/7/134711131/1760150.pdfIn PDF document text
    • http://hookup681.site/engineering_vibration_inman_4th_editionds3rg.pdfIn PDF document text
    • http://lnstagramcopyrightservices.org/purpose_in_writing_the_research_report5cj1x.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4381547/normal_60272fbad018e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4388839/normal_60000b333add0.pdfIn PDF document text
    • http://menbp.online/what_if_netflix_trailer_deutschsu1tf.pdfIn PDF document text
    • https://defasoxajex.weebly.com/uploads/1/3/1/4/131405962/mejujoborofarawenes.pdfIn PDF document text
    • http://devlp.club/60772181287d8n5v.pdfIn PDF document text
    • http://nukicew.xyz/how_to_say_hi_in_chinese_in_english0a95e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4504047/normal_6022d793e30ca.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365636/normal_60384550a947d.pdfIn PDF document text
    • http://lakshmi-store.ru/mebifemebojrsvi7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4406776/normal_5fde38a0355a9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495525/normal_602a53e4891f5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423154/normal_603660f92f0c2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380857/normal_5fd5f9ba0bd7c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off000108ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108AC 5364 bytes
SHA-256: 920fd3448c3d446ff947080bee3ed97cf771983b29821643af3cc26c7911c73d
font_01_sfnt_off00011b17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B17 10320 bytes
SHA-256: d5b1a7c6ac7251289837f513b0e3e3cfb75cc8323cabad3598ed3e388e33d5dc

Open this report in the interactive analyzer, or submit your own file for analysis.