Malicious PDF — malware analysis report

Static analysis result for SHA-256 261f4c0df221eeaf…

MALICIOUS

PDF

70.7 KB Created: 2021-10-01 04:53:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: cf13b107306e80b66b2d8524466c2f86 SHA-1: f619aca3bc41dae13120c60c175a9dab74dff49f SHA-256: 261f4c0df221eeaff838d0e5c6b5cc05d61bd04ba81c9f487d7e23fd83eccad9
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. Numerous heuristics indicate the PDF functions as a link farm, directing users to various external websites, some of which are hosted on compromised WordPress sites or disposable domains. The presence of multiple external URIs and link farm indicators strongly suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • 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.
  • 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://crysiq.ru/uplcv?utm_term=google+android+devices+list PDF link annotation
    • http://artpolinakuzina.ru/pict/file/87207106260.pdfIn PDF document text
    • http://phongkhamthienhoa.vn/images/files/ratetiwem.pdfIn PDF document text
    • https://alirezamirmohammadi.com/images/upload/files/sagosugeme.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/161565cc4ca198---29310633782.pdfIn PDF document text
    • http://www.azurwelcomeservices.com/userfiles/file/nuvapi.pdfIn PDF document text
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1612fef49af02c---dodev.pdfIn PDF document text
    • https://fidelishospice.com/ckfinder/userfiles/files/lexuzarivusizokafanosimo.pdfIn PDF document text
    • http://seatraderhk.com/userfiles/dirubolojanuxukuziwo.pdfIn PDF document text
    • https://projekt-lesen.de/userfiles/file/95385399053.pdfIn PDF document text
    • http://www.hon-ro.hu/userfiles/files/62179379302.pdfIn PDF document text
    • http://robertoantoniz.com/resources/original/file/kababekatowubunujewek.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/tuunhe4kcig6otmrnuu33cr7t1/23612774678.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1613794bc4d9d3---gepoj.pdfIn PDF document text
    • http://tsrmvolontari.it/userfiles/files/63490163549.pdfIn PDF document text
    • http://azbuka-d.ru/ckfinder/userfiles/files/24909945128.pdfIn PDF document text
    • http://jayeonrak.com/upfile_editor/2021/files/bisemidonorawanon.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/ce842914a256539606dd9aeb579425ea/39918511271.pdfIn PDF document text
    • https://mavachhaiphong.com/upload/files/jipizotijasibu.pdfIn PDF document text
    • http://feriaalainversa.com/uploaded/files/37056868034.pdfIn PDF document text
    • http://sin-hua.org/userfiles/61355803448.pdfIn PDF document text
    • http://simpelms.nl/userfiles/files/ralamewudadat.pdfIn PDF document text
    • https://istanajp.com/contents/files/42184063121.pdfIn PDF document text
    • https://vanphongphampmc.com/upload/files/87443468396.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_off0000b19d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB19D 16996 bytes
SHA-256: 7838905d40b5c770f2eb74f9e2105e9cbb85c58a49b79619a6d8d641c82f29a8
font_01_sfnt_off0000dcc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCC0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f4d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4D7 10652 bytes
SHA-256: bc55a0e852d3ba43e199f9d04c93472a00e53a56baebf1e4fc9406059de449ad