Malicious PDF — malware analysis report

Static analysis result for SHA-256 38f15bca0fa0abff…

MALICIOUS

PDF

70.1 KB Created: 2021-09-24 23:36:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 80fab5475f0f4a985c1deffb8d9d723c SHA-1: 055fb71c06926f3f2309e8559fcd8854d139666d SHA-256: 38f15bca0fa0abff6173728c22a2582f02a764e517c8e5f5b69543dfb549d144
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier, indicating malicious intent. It contains numerous embedded URLs, many pointing to compromised CMS upload storage or disposable hosting, characteristic of a link farm used to distribute malicious content or phish for information. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and URL analysis strongly suggest a malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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
  • 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://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135a0b2918ba---gorikag.pdf
    • http://nuuts.mn/uploads/assets/sikusopos.pdf
    • http://j1ent.com/userfiles/file/20210910090454.pdf
    • https://mimpi1pusat.com/contents/files/21632959760.pdf
    • https://bunianco.com/other_files/File/26022234110.pdf
    • https://thucphamtruongxanh.com/Upload/files/lunurovibetovovurot.pdf
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/cc9e4ec7c337e0553eb6d3ac7e5e0109/sesupemewuve.pdf
    • http://hla.vn/upload/files/dadagomexosabowujixe.pdf
    • http://propertiesforrent.com/userfiles/file///reburerimekiro.pdf
    • http://studioboscono.it/userfiles/files/penuwozavizebesirafuvir.pdf
    • http://wintec-samu.hu/uploads/files/9623668322.pdf
    • http://elektron.be/public/userimgs/files/3003935764.pdf
    • http://ocean-ex.com/images/blog/file/mibasodorisupogowazanosen.pdf
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/p8uen5qhqc7v0dm3h0t1h50d37/46957295083.pdf
    • https://unitedpetexpress.unitedreloth.com/ckfinder/userfiles/files/solupe.pdf
    • http://frigotechreina.com/userfiles/files/5366330269.pdf
    • http://khiconghoixuancong.com/Khicong/admin/userfiles/file/3218186024.pdf
    • https://tort-art.ru/userfiles/file/87803458618.pdf
    • http://xn--sanitrprofi-p8a.ch/fckeditor/editor/images/file/kuguxawukufida.pdf
    • http://studiozoppini.com/userfiles/files/vuwebupatev.pdf
    • http://tyextractor.com/d/files/35548528052.pdf
    • https://pisausakti.com/contents/files/64486688249.pdf
    • https://yocarbroker.com/upload/ckfinder/files/dalusaduxubajawedole.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=the+wall+berlin+pink+floyd
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b1b5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB1B5 16792 bytes
font_01_sfnt_off0000c9c7.bin
bd02fd423263317c6afb4ba276d33b0d07ee0fe1b6a37174a90af8acb319b73a
pdf-font-stream PDF embedded font (sfnt) at offset 0xC9C7 15972 bytes
font_02_sfnt_off0000f289.bin
34aea24392133f7e4056503217056e6adef958b1fe375bf5899dcfaa4c95ba61
pdf-font-stream PDF embedded font (sfnt) at offset 0xF289 10724 bytes