Malicious PDF — malware analysis report

Static analysis result for SHA-256 28ae6031d405d503…

MALICIOUS

PDF

77.3 KB Created: 2021-09-17 05:47:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 493c3a6c89174b9535c79b6ecf7be41d SHA-1: 31c1e31194d49e2d5c92baac2c7f8506aac55555 SHA-256: 28ae6031d405d503f3523a52fbd3eefff47c1d0188c366800ed072105d210a3d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised websites or disposable hosting, indicative of a link farm. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this is a malicious document designed to redirect users. The ML classifier and ClamAV detection further confirm its malicious nature, likely serving as a phishing lure or a distribution point for further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 https://ketchas.ru/uplcv?utm_term=adjectives+that+start+with+a+vowel PDF link annotation
    • https://www.borzabadi.com/ckfinder/userfiles/files/mafujigo.pdfIn PDF document text
    • http://jyjwqj.com/uploadfile/file///2021091706260241.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/844dbeef8182d31969997f10b30fa90c/ragejuxik.pdfIn PDF document text
    • http://goodwill.as/userfiles/file/sajavago.pdfIn PDF document text
    • https://bi-kiesabbau.de/cmsimple/images/file/batogelisaxovuzesurowax.pdfIn PDF document text
    • http://szyqjsj.com/UploadFile/file/20210908120738163.pdfIn PDF document text
    • https://bnbtravels.com/ckfinder/userfiles/files/boxuluzaluf.pdfIn PDF document text
    • https://xuantruongtech.com/images/ckeditor/files/nopodeje.pdfIn PDF document text
    • http://okfilm.kr/userData/board/file/mipime.pdfIn PDF document text
    • https://traffictkt.com/viking1/uploads/files/13022631302.pdfIn PDF document text
    • http://pm-ural.com/uploads/files/67940587553.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/kl12st6ugpfb29t8btqufkobp2/bugegoroke.pdfIn PDF document text
    • http://testplanet.nl/uploads/files/37551905164.pdfIn PDF document text
    • https://resulgame.com/calisma2/files/uploads/sixatobokeko.pdfIn PDF document text
    • https://pre-www.bridge-college.com/uploaded/ckeditor/files/5566437645.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134b0cc7717b---vemuxokak.pdfIn PDF document text
    • https://umutisi.com/umut/upload/files/fowibodakimujikawu.pdfIn PDF document text
    • http://tamtamphat.com/upload/files/65446848308.pdfIn PDF document text
    • https://aedwea.com/upload/foto/43314355014.pdfIn PDF document text
    • https://tierrettung-in-katalonien.org/ckfinder/userfiles/files/gigojezirozu.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://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_off0000c7e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7E7 18332 bytes
SHA-256: f19a40461a06e04899668cc9418106761b91cbed5604cbe129a2540fc4292090
font_01_sfnt_off0000f6f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F0F 10624 bytes
SHA-256: 5e4859cc3fe421bf7b6dbb2345d57a2b99b7c40aa480dc39912cbd554760cf90