Malicious PDF — malware analysis report

Static analysis result for SHA-256 3adbcb3e2b648893…

MALICIOUS

PDF

79.0 KB Created: 2021-09-07 23:08:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8358d791de0e1991531d3cc3210dc9ab SHA-1: 8a767ffe468d8b762253f16cccd2b23598ee98ad SHA-256: 3adbcb3e2b6488933ecd14715c3dd94f9177e886843909a862f50262e58ad3fe
156 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to potentially compromised websites or disposable hosting. Heuristics indicate this is a link farm, likely intended to redirect users to malicious content or phishing pages. The ClamAV detection and ML classifier strongly suggest malicious intent, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://chcial.ru/uplcv?utm_term=600+essential+words+for+the+toeic+4th+edition+pdf PDF link annotation
    • http://anpo.vn/upload/files/21657317477.pdfIn PDF document text
    • http://kids-ex.com/31742978708.pdfIn PDF document text
    • https://areicon.com/images/file/1147750538.pdfIn PDF document text
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/70612915139.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/2k459rhtakl1r02fuot8no246m/gifuwajofatuko.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1608448c42a0ff---boxenad.pdfIn PDF document text
    • https://kawanmto.com/contents//files/9215009438.pdfIn PDF document text
    • http://agriturismocorteerbatici.it/userfiles/files/dejaxuj.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/93962869608dde028a8bf312b78d30ca/93342259020.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/q5ls2f5aa0dlroerdv5skumvh8/malewaj.pdfIn PDF document text
    • http://extintoresorigen.com/images/editor/raresexupok.pdfIn PDF document text
    • http://uniqueaddress.in/crm/files/vipibejaniwivit.pdfIn PDF document text
    • https://bladmedyczny24.pl/wp-content/plugins/super-forms/uploads/php/files/70b8452bb048ebb0677b0e5d6e96ef21/31817725402.pdfIn PDF document text
    • https://aromamarketing.md/img/files/bumarosufixa.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4c2c0b151f---42106761277.pdfIn PDF document text
    • http://mtcongnghiepxanh.com/upload/fckimagesfile/32111942593.pdfIn PDF document text
    • https://drsubhashawale.com/ckfinder/userfiles/files/44567597843.pdfIn PDF document text
    • http://yulintimber.cn/d/files/17925682766.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/gbuljit89cuveid9k1t9plduda/27143045418.pdfIn PDF document text
    • http://2018.letnifestiwal.pl/ckfinder/userfiles/files/ratavumufor.pdfIn PDF document text
    • http://andrewsexes.org/clients/867461/File/nunopo.pdfIn PDF document text
    • http://canadanur.com/resimler/files/podatudikekelabaluzefup.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_off0000cb9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB9F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e3b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3B6 11076 bytes
SHA-256: 976dbb32a8f33844ae4601b9746ce65e1e8ace388ffa7a639cacb31a4093cd7c
font_02_sfnt_off0000fd8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD8C 18948 bytes
SHA-256: afedc26c2dff28fa04a23be05eb3e7dbbb7de4b8e082ad7aa1636eddaa19fb82