Malicious PDF — malware analysis report

Static analysis result for SHA-256 db344f480dc8560d…

MALICIOUS

PDF

82.4 KB Created: 2021-09-18 07:18:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 55127e6735a15d9febcd3165e159077e SHA-1: 9405e11fa0655cc759aa652e64ce6783ad1b9f7f SHA-256: db344f480dc8560daf53da6ff6609a3a096519e4dfa272469cf899b7eb07ad36
174 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript and multiple external links, flagged by heuristics as a link farm and potentially malicious. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript and external URLs suggest an attempt to redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • 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 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.
  • 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://www.cerathai.com/image/upload/File/lodibokitariga.pdf In PDF document text
    • http://ncfc.com.tr/ckfinder/userfiles/files/wuvonubabavedevuxi.pdfIn PDF document text
    • https://sanipacific.com/attachment/file/bigilosipegeg.pdfIn PDF document text
    • http://luijkzonwering.nl/image/file/66119814328.pdfIn PDF document text
    • https://transport.frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/48993240333.pdfIn PDF document text
    • http://aroma-es.red/yamituki-n/uploads/files/63725227447.pdfIn PDF document text
    • https://eurotig.ro/file/givenozopixadakigetebos.pdfIn PDF document text
    • https://haltia.mx/sii/ckfinder/userfiles/files/71597786570.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/sekadatitupawokofejaje.pdfIn PDF document text
    • http://faurau.com/luodan/images/userfiles/file/nupufaloda.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/16136039021e74---64395424170.pdfIn PDF document text
    • http://nwatchonline.org/userfiles/file/23632574540.pdfIn PDF document text
    • https://delta-relay.be/userfiles/file/jigutifupafelegot.pdfIn PDF document text
    • https://agrando.cz/files/file/12821810298.pdfIn PDF document text
    • http://anthonyjcincottalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/77345087904.pdfIn PDF document text
    • https://abrasco.org.br/ckfinder/userfiles/files/34493133573.pdfIn PDF document text
    • https://pierrelemagicien.com/userfiles/file/84458059671.pdfIn PDF document text
    • https://stthomasorthodoxchurchsouthpampady.com/userfiles/file/94930634257.pdfIn PDF document text
    • http://jinyezi.cn/upload/14235903777.pdfIn PDF document text
    • http://aluminial.pnh.pt/js/ckfinder/userfiles/files/51819551484.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=ghd+sports+newPDF 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_off0000dcfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCFB 10312 bytes
SHA-256: d6b4c9e1d1e638e92f58fb21787a558d0673912b320af89612b91db39c5c39de
font_01_sfnt_off0000f43e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF43E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C50 18512 bytes
SHA-256: aee53030b8e33749c9f801b5c1cfa446bbf3a84fa7004d135b8ae866b09a3de9