Malicious PDF — malware analysis report

Static analysis result for SHA-256 f0a5727c729a37e5…

MALICIOUS

PDF

73.7 KB Created: 2021-09-24 05:47:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 68f76465be003e5ad6dd922a3b698d91 SHA-1: 841f148d72bdaa5b30c1929d55f93d5d98a3d273 SHA-256: f0a5727c729a37e594c1ed0129bc5ecf16f8544832e96b9e44774424e832f0c6
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of embedded URLs, many of which point to disposable domains and appear to be part of a link farm. The ML classifier strongly indicated maliciousness, and the presence of compromised CMS upload links further supports a malicious intent. The primary goal appears to be SEO poisoning or directing users to potentially harmful content through a series of redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://modaxch.com/userfiles/files/69940625871.pdf In PDF document text
    • http://shanghaiqingchen.com/upload/files/xevulisivuzuvufil.pdfIn PDF document text
    • http://fzcce.com/aimgs/uload/files/fofunapokutozosuvolupopes.pdfIn PDF document text
    • https://jagamimpi.info/contents/files/wezulitatam.pdfIn PDF document text
    • http://sevinctekstil.com/resimler/files/masofimexa.pdfIn PDF document text
    • http://zkmeiqi.com/admin/ckfinder/upfile/files/nusepinuku.pdfIn PDF document text
    • https://venusnvs.com/userfiles/file/latutijozem.pdfIn PDF document text
    • https://brihat-group.com/assets/userfiles/files/xinujaxogemize.pdfIn PDF document text
    • http://herve-coiffure.ci/files/48312961037.pdfIn PDF document text
    • http://tecnoservizi.com/userfiles/files/70314879754.pdfIn PDF document text
    • https://un7un9b3rl1pa7-99.com/contents/files/wijewonatofatoxifarek.pdfIn PDF document text
    • http://abcbyspu.com/ckfinder/images_store/files/zovov.pdfIn PDF document text
    • http://wonsakai.com/uploads/files/1220079092.pdfIn PDF document text
    • http://oroblupiscine.it/userfiles/files/39425325655.pdfIn PDF document text
    • http://ivankotov.ru/img/lib/file/66992659190.pdfIn PDF document text
    • http://zlhk.ru/upload_picture/file/88986017625.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1613d03d19fbfd---jozaxexomarisumukasixamu.pdfIn PDF document text
    • http://hengtaixin.com/HangShun/ckfinder/userfiles/files/53394181392.pdfIn PDF document text
    • http://bangdinhphucat.com/quangbasanpham/app/webroot/upload/image/files/12723007792.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/16147e74974135---kawewifokojuzagogi.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a810a20f37---7258696226.pdfIn PDF document text
    • http://xn--9i1b14l32gg2dsybq3b.com/upload/fckeditor/file/97834056090.pdfIn PDF document text
    • https://foursservices.com/nbloom/fckuploads/file/gikuvexof.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=recover+deleted+videos+android+redditPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bfb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d7ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7CA 10472 bytes
SHA-256: a45f0fe5c01a46c0323e570d9a8dd3f31b7233b6c55a8cf0a0c4e3ae443e29d0
font_02_sfnt_off0000efb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFB5 16096 bytes
SHA-256: 76dce4a4ba5a2be8a5afc6c7ddda7670e15d99e0329e669403e04c30b3423538