Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac75bcec44e0f502…

MALICIOUS

PDF

81.1 KB Created: 2021-09-08 15:22:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e689d1c5a4ec323752a28e7f52f6ac3a SHA-1: 22931dcfcf612933ed04668217ddfe7b099341e0 SHA-256: ac75bcec44e0f502b1fa323f37e603423e2a79d47c369ccd5cdac50b73be7291
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to lead users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. The presence of multiple link farm heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://duef.ru/public/file/wulumezelekide.pdf In PDF document text
    • http://precisao.org/files/files/43805517406.pdfIn PDF document text
    • http://stilistspb.online/public/files/uploads/files/51515750228.pdfIn PDF document text
    • http://dispensapertutti.com/userfiles/files/36850115228.pdfIn PDF document text
    • http://loadcell.vn/Images_upload/files/33983255205.pdfIn PDF document text
    • http://xn--80aadcnaeutgftohcogh8i8dsc.xn--p1ai/pict/file/55009825434.pdfIn PDF document text
    • http://kedehg.com/ckfinder/userfiles/files/bavekumir.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/11999036633.pdfIn PDF document text
    • https://jamuiboe.com/webroot/upload_media/kebesulixevevuzad.pdfIn PDF document text
    • http://angelcabrera.com/FCKfiles/file/nuropajajuvevir.pdfIn PDF document text
    • http://versobrokers.eu/userfiles/files/48701387093.pdfIn PDF document text
    • http://massimosusto.eu/userfiles/files/29478233607.pdfIn PDF document text
    • https://bywuf.org/upload/editor/files/8277328096.pdfIn PDF document text
    • http://cofetariafraguta.ro/UserFiles/file/16317599594.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/7aaa55a2e2796b0177fc2328e729520f/nonoj.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612f6ac4c77b5---kelibizuno.pdfIn PDF document text
    • http://air-con.ru/upload/files/52699425507.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/2fkjt1m6c65qi8hck2u62t8f7a/piliwanisibenuleberisek.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eaaf46dcdc---44735339139.pdfIn PDF document text
    • http://fuguchair.com/upfolder/e/files/20210906140155.pdfIn PDF document text
    • http://nguyenhungstone.com/uploads/image/files/zewaruzufu.pdfIn PDF document text
    • http://parkety-patemal.sk/files/file/50813372468.pdfIn PDF document text
    • http://electric-kernbichler.at/nuvonasuropanikogirik.pdfIn PDF document text
    • http://studiotecnicodavico.eu/userfiles/files/rijovimosikenixok.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=tratamiento+candidiasis+en+hombres+pdfPDF 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_off0000d841.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD841 18100 bytes
SHA-256: 20cd33025145629ead68a55b4a67d487f064c31225ec78f63234cfb4e0df9055
font_01_sfnt_off000105cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105CF 10944 bytes
SHA-256: 52fa907a47b6e587ae8582ea35aaff890949c3fb572284941402bf5cf01da843
font_02_sfnt_off00011ebc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EBC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1