Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf5aa8b35ebccc6d…

MALICIOUS

PDF

69.6 KB Created: 2021-10-01 21:14:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: d403f25dc24a3b5ea1623f6743c37441 SHA-1: 02ad5bc7bcbd27e17994b95202484bf62067a045 SHA-256: cf5aa8b35ebccc6d378ad869003e14685bba387c581a4ecd8bbca796e7987b31
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to disposable domains, and is flagged by ML classifiers and ClamAV as malicious. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a link farm strategy, suggesting the PDF is used to redirect users to potentially malicious content. While no scripts were explicitly extracted, the nature of the links and the detection suggest a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://cabsfromheathrow.com/userfiles/file/94630837428.pdf In PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/161319bdb7e52f---ximibosigagujosipapabowol.pdfIn PDF document text
    • https://hgb.se/filer/file/4408773390.pdfIn PDF document text
    • http://abimobiliare.pl/pliki/File/1181757558.pdfIn PDF document text
    • https://resttour.com/images/userfiles/files/zubonuzerumij.pdfIn PDF document text
    • https://hotelpancharatna.com/assets/userfiles/files/tugagew.pdfIn PDF document text
    • https://shopinhome.com/ci/userfiles/files/419872107.pdfIn PDF document text
    • https://gsc-tw.com/userfiles/file/36016801063.pdfIn PDF document text
    • http://paradisetnl.com/FileData/ckfinder/files/20210923_1533333378C587F1.pdfIn PDF document text
    • https://przyklejki.pl/userfiles/35577965933.pdfIn PDF document text
    • http://gfzgt.ch/upload/file/66550062507.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161399ae88ee66---bebikefawifimozotanu.pdfIn PDF document text
    • http://kingsfci.com/userfiles/file/37524472567.pdfIn PDF document text
    • http://unternehmensberatung-hegenbarth.de/userfiles/file/41552986670.pdfIn PDF document text
    • https://viessmannboilers.ca/fck_upload/file/fekugibas.pdfIn PDF document text
    • http://confidenzacsapagy.hu/upload/79452961506.pdfIn PDF document text
    • http://barahi.com/assets/userfiles/files/noranatafikofifemat.pdfIn PDF document text
    • https://szabobuszrendeles.hu/files/files/toxikujaku.pdfIn PDF document text
    • http://polaryachtmanufactory.com/res/wysiwyg/file/12316514722.pdfIn PDF document text
    • http://kvarkeno56.ru/userfiles/file/73054601850.pdfIn PDF document text
    • http://wangguanhardware.com/userfiles/file/21250761365.pdfIn PDF document text
    • http://hopkim.vn/upload/files/mujuxonulem.pdfIn PDF document text
    • https://festacontinua.it/public/file/demupupefejokeponefine.pdfIn PDF document text
    • http://phucuongplus.com/upload/files/69068298013.pdfIn PDF document text
    • https://villamishkan.com/310renonew/front/images/files/bubivinofodemubopijozenud.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=no+apps+are+downloading+on+my+iphonePDF 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_off0000b27f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB27F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA96 10920 bytes
SHA-256: 4ef836ce9ff3d6241606d28ba85218038c960d4c4d5e05fa800bc6aa23f0b860
font_02_sfnt_off0000e375.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE375 14612 bytes
SHA-256: 4a6975761b324637f549edf8f9bdbbbccfeb69bb4caf6c1c0e184a8481355488