Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c6f0e595bcbe35f…

MALICIOUS

PDF

71.6 KB Created: 2021-09-17 01:44:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d332dcdbe4dbab5728d0c6a81605fd63 SHA-1: 84c805a450a136eab888810a00acc9ef7d564593 SHA-256: 4c6f0e595bcbe35f6a81740122e07a4cf4d62c2d9690fbbb4f84c09ff169a924
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicative of a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are consistent with techniques used to deliver second-stage payloads or redirect to phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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=brave+new+world+ebook+download+pdf
    • http://d-innovation.com/upload/files/11728474819.pdf
    • https://gabconstruction.com/ckfinder/userfiles/files/nulawuvudewu.pdf
    • http://kokocurry.gm/userfiles/file/10132808574.pdf
    • https://open-call.fr/uploaded/files/tisulufemadupevisaz.pdf
    • http://tortsurprise.ru/upload/redactor/files/zirinutatuxofere.pdf
    • http://seanmore.com/userData/board/file/dupokoputu.pdf
    • http://capitaldanceacademy.com/userfiles/files/12887285715.pdf
    • http://assessmentinsight.com/ckfinder/userfiles/files/rakozozovemitivamizuzaf.pdf
    • http://avision-italia.com/userfiles/files/46875505339.pdf
    • http://roomyab.ir/basefile/roomyabir/files/16019408147.pdf
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140b03bf2312---24549110155.pdf
    • https://pataniforum.com/admin/jquery/ckfinder/userfiles/files/fekumoxutez.pdf
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/ucmt9hc1phbl88asmeo4cgpgt2/96728892441.pdf
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142b2ae2a315---3344884256.pdf
    • http://alacarte-design.de/userfiles/file/kaziwiwokuxi.pdf
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140530d369ba---baxalutamevofogiwiv.pdf
    • http://geraldinekilkelly.ie/87967129537.pdf
    • https://ymy-tea.tw/upload/files/kiveviloxijesi.pdf
    • http://classtool.info/upload/files/xoreregejavuxu.pdf
    • http://lokalsport.no/userfiles/file/91166188978.pdf
    • https://highlander-inn.com/assets/userfiles/files/kamosirutimibo.pdf
    • https://xn--fct8ml6mwue.tw/uploads/files/vazip.pdf
    • https://www.scmsgroup.org/ckfinder/userfiles/files/duzozalinisogodis.pdf
    • http://stnicholasway.com/userfiles/file/riduv.pdf
    • 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_off0000b7dd.bin
43eb5c330690ab0cc37fca99506b6338a3ae7217468af28c7353c65756efa06d
pdf-font-stream PDF embedded font (sfnt) at offset 0xB7DD 10572 bytes
font_01_sfnt_off0000cfee.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFEE 16792 bytes
font_02_sfnt_off0000e800.bin
ed5ae309a765b264002961bf59112b4bca96e28c95ed12c4b3a6c24f4b753629
pdf-font-stream PDF embedded font (sfnt) at offset 0xE800 15796 bytes