Malicious PDF — malware analysis report

Static analysis result for SHA-256 50dfa77cd57a5637…

MALICIOUS

PDF

78.9 KB Created: 2021-09-09 01:34:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 37b3447274af2670403157e53394a151 SHA-1: 5bf5ac289b5adfa5bb7aaa2fe6a137bd487a53f5 SHA-256: 50dfa77cd57a56378d37187d41fc351662cbc73b7778bacab7e6e16ee67b0567
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document contains multiple links to distinct, potentially disposable hosts, suggesting a phishing or spamming operation. While no scripts were directly extracted, the PDF structure and embedded URLs point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • 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.
  • 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://anhuifan.com/upload_fck/file/2021-9-9/20210909005333287819.pdf
    • http://ceramkgres.ru/userfiles/file/51932907013.pdf
    • http://choinka4x4.org/cms/files/file/6194598317.pdf
    • http://commissioncollectionlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/7737973160.pdf
    • http://esistore.lu/userfiles/file/xijusujujedopuxe.pdf
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/favugi.pdf
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/dcjm9a9rtfulgmohh0rvak254c/78532560671.pdf
    • http://linuxnewyork.com/draft/media/5350410388.pdf
    • https://editionsitaliques.com/userfiles/file/mosofivob.pdf
    • http://www.offshoreyachts.net/web_upload/editor/files/zoxonabuninu.pdf
    • http://www.ktgroup.co.uk/ckfinder/userfiles/files/96659134164.pdf
    • http://boletin.alicantehosteleria.com/lib/ckfinder/userfiles/files/64245728716.pdf
    • http://slsnn.ru/content/files/xazefiveselaz.pdf
    • http://zkpower.net/upload/files/22645735470.pdf
    • https://binarbaidrealestate.com/public_html/userfiles/file/67816960466.pdf
    • http://fairway.cc/images/blog/file/28129149793.pdf
    • http://hcwan.com/userfiles/file/detadusekitewuluzupagovuw.pdf
    • http://xn----ftbkdcamitb5h.xn--p1acf/files/fck/file/fujonuvatevagemuveno.pdf
    • http://mrpokedb.com/uploads/files/94297217294.pdf
    • http://maremio.ru/admin/ckfinder/userfiles/files/rewejifazajatem.pdf
    • http://dok-vo.ru/userfiles/file/44390265374.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=car+park+mod+apk
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d220.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD220 16792 bytes
font_01_sfnt_off0000ea37.bin
9411fcb251cb4beb66210d53b21b06a45e2fc5a12a9b0f3d07e194a0295167ad
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA37 10036 bytes
font_02_sfnt_off00010074.bin
21e6e39a8eb3c110da42f7cf3b14379585e0600121251df2849d028ad5f08e1e
pdf-font-stream PDF embedded font (sfnt) at offset 0x10074 17792 bytes