Malicious PDF — malware analysis report

Static analysis result for SHA-256 c876c0e01aece9f2…

MALICIOUS

PDF

76.9 KB Created: 2021-09-23 22:18:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f9c1f2ebf7a5e382a575756d4ddfd830 SHA-1: 4f491478f04c26ba0b3c3ac37f0fb7d38a03f4ac SHA-256: c876c0e01aece9f2e70bc42b6ee0af4c9d3a7443642260fb0cf5fd914490d0e2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous embedded URLs pointing to various domains, coupled with the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic, suggests the document is part of a link farm designed to manipulate search engine results or distribute further malicious content. No scripts were extracted, and the document body was unreadable, but the overall structure and heuristic firings strongly indicate a phishing or content distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://gamecoast.by/uploads/files/99008625210.pdf In PDF document text
    • http://restaurant-lyons.fr/userfiles/file/bimifetosag.pdfIn PDF document text
    • http://lovec.bg/root/ckfinder/userfiles/files/94309128625.pdfIn PDF document text
    • http://fitviewer.info/files/file/1813407857.pdfIn PDF document text
    • http://www.fd.ntou.edu.tw/ckfinder/userfiles/files/togeritudadetitaze.pdfIn PDF document text
    • https://kitapkapla.com/upload/ckfinder/files/22197415498.pdfIn PDF document text
    • http://berbun.com/user_img/file/23976137709.pdfIn PDF document text
    • https://hiddencliff.kr/FileData/ckfinder/files/20210906_B79E3A9B8DD2D139.pdfIn PDF document text
    • https://sasalidayanisma.org/uploads/file/58969911815.pdfIn PDF document text
    • http://first-group.kr/ckupload/files/sirutozalotizamixavira.pdfIn PDF document text
    • http://cke.hk/userfiles/49154738026.pdfIn PDF document text
    • http://kovacsoltvaskerites.hu/images/file/poboduluxosege.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16149d03cc817e---zapoki.pdfIn PDF document text
    • http://launensia.cz/ckfinder/userfiles/files/97471554434.pdfIn PDF document text
    • http://zehanbiopharma.com/upload/files/gavalawoxijaremofi.pdfIn PDF document text
    • https://sowlindia.com/userfiles/file/89555811381.pdfIn PDF document text
    • http://epmresearch.org/userfiles/files/7293130970.pdfIn PDF document text
    • https://duragloss.pl/userfiles/file/vuvapekujelukuw.pdfIn PDF document text
    • https://cytokin.ca/upload/editor/file/zogafozirefupigasewamuwa.pdfIn PDF document text
    • http://electrogalicia.com/electrogalicia/recursos/archivos/zezebedifeko.pdfIn PDF document text
    • http://collectifff.be/imgdb/accueil/files/55893185444.pdfIn PDF document text
    • https://maftplayer.net/calisma2/files/uploads/26245151358.pdfIn PDF document text
    • http://stagelight.pl/userfiles/files/funugenitapilamazavami.pdfIn PDF document text
    • https://bachson.net/upload/file/32082952186.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=1337x+free+moviesPDF 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_off0000cab5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAB5 17048 bytes
SHA-256: d0de803e525474fba1e9e8673f6480c6feed1c2d434c9756fcc8a3c33f57313b
font_01_sfnt_off0000f68b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF68B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ea2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EA2 10312 bytes
SHA-256: 4311b9d114a8c61261f52d14fc86dfa6272768536ba55ecf3eed2cfc298b9c6e