Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a41dac383025c8c…

MALICIOUS

PDF

83.4 KB Created: 2021-09-14 10:20:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 28a3f4488dcf31996b879a88755192fb SHA-1: ffbc762f607b2d7e88bcc7ae85ee11c6ad4cf566 SHA-256: 3a41dac383025c8c5237bb4d1a05cfe26415b913a5caab6918832d0ee34247fc
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the PDF likely contains numerous links to external sites, suggesting a phishing or redirection attempt. The embedded JavaScript likely facilitates the redirection to these external URLs, which could host further malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://szintai.hu/ckfinder/userfiles/files/gozopedafizeru.pdf In PDF document text
    • http://nayyaralidada.com/alpha/ckfinder/userfiles/files/pamigefidigeleroxiwufawip.pdfIn PDF document text
    • https://szpital-sulecin.pl/images/fckfiles/file/24349337853.pdfIn PDF document text
    • http://jysfh.com/upload_fck/file/2021-9-1/20210901063739134097.pdfIn PDF document text
    • https://pediatricpotentialsnj.com/PP/PPpng/files/22596294834.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/bb3026068e3604a06d1b001b2533e216/regilazidifabozijigom.pdfIn PDF document text
    • http://nyitotthaz.hu/userfiles/files/20341254858.pdfIn PDF document text
    • http://iccjsc.com/images/uploads/files/bufenirupokumas.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f4868b7a32---12065324112.pdfIn PDF document text
    • http://alnadaoil.com/userfiles/file/11583791336.pdfIn PDF document text
    • https://www.vek-bg.com/app/templates/js/ckfinder/userfiles/files/wemefoneroz.pdfIn PDF document text
    • http://robwalker.net/fckupload/file/larekalazedafimuki.pdfIn PDF document text
    • http://ceramkgres.ru/userfiles/file/77840295279.pdfIn PDF document text
    • http://bkdesign.ee/userfiles/file/tamop.pdfIn PDF document text
    • http://e2ingenieros.com/ckfinder/userfiles/files/64083103493.pdfIn PDF document text
    • https://autopsrus.aerovents.com/ckfinder/userfiles/files/lodedolapelibepisukerosaz.pdfIn PDF document text
    • http://learnazia.com/fck/imagesfile/86043543784.pdfIn PDF document text
    • http://stjconsulting.it/userfiles/files/69836523549.pdfIn PDF document text
    • https://korovin.org/site/img_ufiles/dinopisiwuduxudunuk.pdfIn PDF document text
    • https://smsenerji.com/resimler/files/lasimuwivevira.pdfIn PDF document text
    • http://studiotecnicodama.it/userfiles/files/71886972728.pdfIn PDF document text
    • http://kingkady.com/uploadfile/files/63355380283.pdfIn PDF document text
    • http://tygodnikzuzlowy.pl/ckfinder/userfiles/files/48223546952.pdfIn PDF document text
    • http://tunapvietnam.thietbiotoviet.com/Images_upload/files/10114156381.pdfIn PDF document text
    • https://dynasty888.com/image/files/20210902_212615.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/85237727588.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=hack+code+rosPDF 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_off0000e1f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1F6 18272 bytes
SHA-256: 1d8447d82262e4d46872185e2969b05f7784bf227b6e4ebe951f7b38db634811
font_01_sfnt_off00011116.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11116 10104 bytes
SHA-256: a61964d6c3f58fb4d69180af53827aa0aba40254a61a403729761acdb101b3ed
font_02_sfnt_off000127bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1