Malicious PDF — malware analysis report

Static analysis result for SHA-256 891bb3961157ee36…

MALICIOUS

PDF

72.7 KB Created: 2021-09-20 07:55:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 22c4b49af7a7d5ba64a37dfdcf7f36e2 SHA-1: 5ddf7c07d6440294ead6f5a0d31dc68cebd62c16 SHA-256: 891bb3961157ee36a58919fa9de5645c437e965ab3525b88ecd924aca5ce6e5f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting, indicating a link farm designed to lead users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the analysis relies on URL heuristics and AV detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://eternaseguros.net/files/files/dufavadafekemovovidofagi.pdf In PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16144a7e4e8f73---70655558407.pdfIn PDF document text
    • http://sayarbobinaj.com/file/82577991819.pdfIn PDF document text
    • http://aaronandanthony.com/userfiles/files/96781883004.pdfIn PDF document text
    • https://majubesar.info/contents/files/51881097696.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/16147f96c37fe9---45882057776.pdfIn PDF document text
    • https://fallahi-sch.com/userfiles/file/boxokarevazelutomek.pdfIn PDF document text
    • https://granitabrasive.com/editor_up/17072578535.pdfIn PDF document text
    • http://architectureanddesign.it/userfiles/files/53867855208.pdfIn PDF document text
    • https://primer-spb.ru/files/files/kuridanu.pdfIn PDF document text
    • http://apisicul.com/userfiles/files/vupipelojamur.pdfIn PDF document text
    • http://studioguidobarbieri.it/userfiles/files/15074441235.pdfIn PDF document text
    • http://we-women.de/default/files/uploads/file/popilox.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1614558607e010---80360146294.pdfIn PDF document text
    • http://njbeihang.com/uploadfile/file///2021091805594179.pdfIn PDF document text
    • http://phanphoiongnhuahoasen.vn/upload/files/70310851713.pdfIn PDF document text
    • http://aow.infogestnet.it/ckfinder/userfiles/files/wexibipatopu.pdfIn PDF document text
    • https://dacinsara.ro/fckfiles/file/zoxawamuvana.pdfIn PDF document text
    • https://abzesolar.com/uploads/files/fimedutofa.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/6d6a463c4423c8a72e83c821fcdbddb9/10672425076.pdfIn PDF document text
    • https://deconkhoemanh.com/wp-content/plugins/super-forms/uploads/php/files/evnvl6i6pqt16oicfnrhe8atol/76540630402.pdfIn PDF document text
    • http://elskup.pl/images/assets/file/42426496270.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=watch+god+of+highschool+kissanimePDF 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_off0000b9a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9A3 16384 bytes
SHA-256: 6d576659f27025b160813cac94fbe129c18d5575bf5a1e6e7541b1b5af886f49
font_01_sfnt_off0000e433.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE433 10908 bytes
SHA-256: 07257c24de8b0de6a6a5d532ff02b98fce236dd97d8c1d702828f9f61084f125
font_02_sfnt_off0000fd1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD1F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1