Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8d8136b09376620…

MALICIOUS

PDF

79.1 KB Created: 2021-09-21 23:04:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 17aa7abac888e38052006ce9fcfb7a7e SHA-1: 176a1e56d82ae1402faa1d18f3762daaeae98238 SHA-256: d8d8136b09376620278def7176a12dbd883f8e62a70f7e77d71a07ce9c5a0fc5
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by an ML classifier as malicious with high confidence. It contains numerous embedded URLs, many pointing to disposable domains, and one heuristic specifically identified it as a link farm. The document body, though heavily obfuscated, suggests a 'pet listening test' lure, which is a common tactic for phishing or malware distribution. No scripts were extracted, but the presence of multiple external URIs indicates an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 4

  • 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://towa-aaa.jp/userfiles/file/21574677553.pdf In PDF document text
    • http://abdon.madteam.net/ckfinder/userfiles/files/92557556114.pdfIn PDF document text
    • http://orthodoxvaidikasanghom.org/userfiles/file/pupijum.pdfIn PDF document text
    • http://futimisdev.com/userfiles/file/4139134761.pdfIn PDF document text
    • https://eko-briketes.lv/userfiles/files/4640175463.pdfIn PDF document text
    • http://windmill-bv.com/userfiles/files/70255855179.pdfIn PDF document text
    • http://lycee-elm.com/userfiles/file/sijafiganolawamusoruput.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/u44lbgro7io7hhk65nn82pts90/wilebinipepabugajom.pdfIn PDF document text
    • http://chanhbon.vn/media/ftp/file/30695161163.pdfIn PDF document text
    • http://xnucleus.com/members/member_images/files/33923277643.pdfIn PDF document text
    • http://thechelseaff.com/user_uploads/files/walugemaxuzoxiluzeduvu.pdfIn PDF document text
    • http://drironcat.com/images/file/7558315505.pdfIn PDF document text
    • http://ljjxmining.com/uploadfile/file///2021091609584925.pdfIn PDF document text
    • https://bem-sa.com/img/file/87760047897.pdfIn PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/33406084779.pdfIn PDF document text
    • https://atputasbazes.lv/images/userfiles/files/jekotasaridunolipepol.pdfIn PDF document text
    • http://patriabrno.cz/userfiles/files/tilonujuduwevikuxo.pdfIn PDF document text
    • https://bunyaminerdemir.com/resimler/files/24489230794.pdfIn PDF document text
    • http://ruishikaishi.com/upload/content/files/2021/09/20210916111406.pdfIn PDF document text
    • http://m3hotels.com/userfiles/file/fenogimigovuvefarax.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613f1a721cbcd---lilavap.pdfIn PDF document text
    • http://hyosangjo.com/userfiles/file/20210903091153.pdfIn PDF document text
    • https://hebatkeren88.com/contents/files/77219011938.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=pet+listening+test+pdf+with+audioPDF 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_off0000c6a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6A6 10864 bytes
SHA-256: e8b7dd31fcc206dcd2a66146867ad09bac1347c650299c281ea954fe8ffaf0cc
font_01_sfnt_off0000df91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF91 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f7a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7A3 20912 bytes
SHA-256: d399cad9e2f6c2fc1af6fbf0fd8d504a057983d7a9a27bf6b1142b16c429c912