Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4b6549231bc29f7…

MALICIOUS

PDF

71.2 KB Created: 2021-09-09 04:37:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 8d2439ac1ff49e99ae98cc0dbfb363fe SHA-1: 894bedd6529eb8ae43a71f0b444adcd55c6591a2 SHA-256: e4b6549231bc29f776c9cc6f68c33ef6fa9356a32d2d928ff9df24176d446a13
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple links to external resources, with several heuristics indicating a link farm on disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the presence of numerous external links points to an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://asdgolfclubtoscana.com/writable/public/userfiles/file/wakifafugi.pdf In PDF document text
    • https://irepairplus.nl/app/webroot/files/userfiles/files/59048306209.pdfIn PDF document text
    • http://newgrids.com/userfiles/file/mosikokuwajolazogis.pdfIn PDF document text
    • http://xn--80aaa1acmiejxr6d7fg.xn--p1ai/data/files/mefixikun.pdfIn PDF document text
    • https://blogsma.com/files/42863639768.pdfIn PDF document text
    • http://mjengo.org/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/97902085250.pdfIn PDF document text
    • http://ambulatorioveterinarioscapindandrea.it/userfiles/files/71725041445.pdfIn PDF document text
    • https://brawlcall.jordanadams.com/ckfinder/userfiles/files/16169945383.pdfIn PDF document text
    • https://huaienclinic.com/uploadpic/files/lepizidur.pdfIn PDF document text
    • http://yuh-tarng.com/userfiles/file/65964299761.pdfIn PDF document text
    • https://greenfuturevietnam.com/Upload/files/87708425284.pdfIn PDF document text
    • http://mstreatmentadvances.com/userfiles/files/sifijoguxotibeko.pdfIn PDF document text
    • http://chinastom.ru/userfiles/file/72322804162.pdfIn PDF document text
    • http://henzefashion.com/userfiles/file/55903142079.pdfIn PDF document text
    • http://jysfh.com/upload_fck/file/2021-9-6/20210906171443305619.pdfIn PDF document text
    • http://claudiamelchior.it/images/file/34151071952.pdfIn PDF document text
    • https://ka-base.no/images_content/file/18233226261.pdfIn PDF document text
    • http://mintaialuminum.com/d/files/53320695524.pdfIn PDF document text
    • http://kolbiko.com/images/uploads/file/58158331270.pdfIn PDF document text
    • http://sindikat777.ru/ckeditor/ckfinder/core/connector/php/uploads/files/25555493628.pdfIn PDF document text
    • http://ruben.pl/ckfinder/userfiles/files/dibafi.pdfIn PDF document text
    • http://gancza.pl/userfiles/file/55629126772.pdfIn PDF document text
    • http://salwex.hu/file/35612931495.pdfIn PDF document text
    • https://horacebatten.com/ckfinder/userfiles/files/xovelebukebanipom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=how+to+scan+barcode+on+phone+screenPDF 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_off0000b83d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB83D 10692 bytes
SHA-256: 6b8bdac85134aefa7b8a2b42f1b0ab8578d667fdd0b0bf47af4e7538ae38d3da
font_01_sfnt_off0000d086.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD086 15324 bytes
SHA-256: 0beca573db261c165f49b3ce78affc46b6a3a13665ed6bf61b40b2aba5781528
font_02_sfnt_off0000f6fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1