Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a264bbbe33e354d…

MALICIOUS

PDF

71.5 KB Created: 2021-09-12 15:21:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8c310e3a6602f1239814d5fee9911d28 SHA-1: 76c562dff8a812db9b6a704f3a07f2236b410ea1 SHA-256: 8a264bbbe33e354d6c2cf1c2b722dd5e45ee82d240f2f86e8310ebe13c3082ba
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to disposable hosting and are used in link farms, suggesting a phishing or malware distribution scheme. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, likely intended to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://krisoc.ru/uplcv?utm_term=how+to+download+plants+vs+zombies+in+laptop PDF link annotation
    • https://mlbcsimleague.com/ckfinder/userfiles/files/rovogabilu.pdfIn PDF document text
    • https://nls.vn/upload/files/13572603862.pdfIn PDF document text
    • https://praktijk.zorglink.nl/ckfinder/userfiles/files/36447096969.pdfIn PDF document text
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/161321315afb80---gepom.pdfIn PDF document text
    • http://squarcialupirelaxinchianti.com/writable/public/userfiles/file/90737084819.pdfIn PDF document text
    • http://hillsdalehorseboarding.com/ckfinder/userfiles/files/mojita.pdfIn PDF document text
    • https://piti.leaddeehub.com/userfiles/files/wefuzuvajerujobalefamez.pdfIn PDF document text
    • http://mariautonoleggiomarsala.it/userfiles/files/puroweziwaxa.pdfIn PDF document text
    • http://kemenyseprosiklos.hu/upload/file/38938148320.pdfIn PDF document text
    • http://mtjjt.com/2013/upload/article/files/210908115449079109km9an.pdfIn PDF document text
    • http://aqs-group.it/userfiles/files/83220341561.pdfIn PDF document text
    • https://shivajigrihnirman.com/singhania/downloads/file/jiboxodutafa.pdfIn PDF document text
    • http://xn----otbb6ahq3d.xn--p1ai/ckfinder/userfiles/files/98201594561.pdfIn PDF document text
    • http://mylodge-naoshima.com/images/blog/file/10253844334.pdfIn PDF document text
    • http://aven.su/userfiles/file/63391966384.pdfIn PDF document text
    • http://carbontuning.ru/file/jivop.pdfIn PDF document text
    • https://cakesandcupcakes.net/userfiles/files/44176359742.pdfIn PDF document text
    • http://www.leasebridge.com/CKUPimg/files/20446311431.pdfIn PDF document text
    • http://ccspatti.org/userfiles/file/tavudorujumenozo.pdfIn PDF document text
    • http://d-innovation.com/upload/files/polaxuki.pdfIn PDF document text
    • http://montpellier-businessplan.fr/mbp/upload/images/images/upload/ckfinder/ripumixa.pdfIn PDF document text
    • http://lingeriedediva.com/UploadFile/file/2021090701545473499.pdfIn PDF document text
    • http://bookblog.kr/data/file/files/pubodenepe.pdfIn PDF document text
    • https://dubaimotorcycletours.dubaimotorhomerentals.com/uploaded_images/files/bijurefixa.pdfIn PDF document text
    • http://tienphat.vn/imagesflashupload/file/25337563448.pdfIn PDF document text
    • http://sangiorgioautoservizi.com/userfiles/files/97822918622.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_off0000b70e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB70E 15852 bytes
SHA-256: 49b9d16648810c26add10524b39b8ae2e676925aea004d543814ce50e15660a3
font_01_sfnt_off0000df3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF3E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f755.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF755 10796 bytes
SHA-256: 565c2ac2d16548d04788cb45ce56416b3130bd24e48deb8cc3f7210d19a37709