Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa20c54a92fe79dc…

MALICIOUS

PDF

76.0 KB Created: 2021-09-22 15:54:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: d35159b3921243c946f27519d8234553 SHA-1: 3d86db2c312f715cb814d4a57cb466a4a59e29ec SHA-256: aa20c54a92fe79dcad919c918891719615e51c00eb9ee3421f4b13f0f8f309bd
204 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and multiple external links, several of which point to compromised CMS uploads or disposable hosting, indicating a likely attempt to download and execute a secondary payload. The ML classifier and ClamAV detection strongly support its malicious nature, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://mispuntossaga.com/campannas/file/bajemikosubusobi.pdf In PDF document text
    • http://kibbkw.com/uploads/files/sizusidenigagowomefijowo.pdfIn PDF document text
    • https://gestionarival.com/userfiles/file/bemel.pdfIn PDF document text
    • https://superiorservicesandsolutionsfl.com/nbloom/fckuploads/file/vijijas.pdfIn PDF document text
    • http://leebyunghun.kr/new/upload/board/files/45926438791.pdfIn PDF document text
    • http://flyingfish-stay.com/userfiles/file/29851169666.pdfIn PDF document text
    • http://architettobotteonpierpaolostudioabacus.it/userfiles/files/78966413948.pdfIn PDF document text
    • https://cicasoftavukatwebsitesi.demowebsiteleri.com/upload/files/mefukudebenavajedejugabon.pdfIn PDF document text
    • https://u15.ch/ckfinder/userfiles/files/68260847226.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/c04760d2402fda736bc155029253dec8/73874703021.pdfIn PDF document text
    • https://beeshark.ro/app/webroot/files/userfiles/files/68749962656.pdfIn PDF document text
    • https://kozhikodedeaf.org/admin/my_files/file/64237814735.pdfIn PDF document text
    • http://phuketdriveschool.com/userfiles/file/padawitewuvofewuwovag.pdfIn PDF document text
    • https://indobaliart.com/sitefiles/file/bovezesugo.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/c8cea2b53699e2cf6a631b03e3085dfb/37124733560.pdfIn PDF document text
    • http://www.palmettoexpresslanes.com/system/js/back/ckfinder/userfiles/files/zopig.pdfIn PDF document text
    • http://louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/60845381676.pdfIn PDF document text
    • http://urs-certification.com/gais/image/file/tejelixugugafuviko.pdfIn PDF document text
    • http://ccswcd.com/userfiles/file/vipamedunoxepujokusozim.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161307c1facd78---nudobo.pdfIn PDF document text
    • https://nyig.com/files/file/68260089743.pdfIn PDF document text
    • http://studiotecnicobergamaschi.it/userfiles/files/teluba.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=hebrew+keyboards+for+androidPDF 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_off0000c47a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC47A 10628 bytes
SHA-256: 2192190050aa4c280c5a361d5f5e85a8eb72575d042de75b8f64d874b2497144
font_01_sfnt_off0000dcee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f500.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF500 17480 bytes
SHA-256: 4a5bec77cd5e595b25577db6e814a4ef16f64d94ecb8f03d7380fd0cbfcd450f