Malicious PDF — malware analysis report

Static analysis result for SHA-256 166d15d764822ca9…

MALICIOUS

PDF

81.4 KB Created: 2021-09-22 12:06:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: da477ea3ffd21e18f8b9897ef6847a6a SHA-1: a9d3e7e21663ed1cf81a53c50cf3f16c8c0b8812 SHA-256: 166d15d764822ca94e559c188360958dff66acfea4241e5e42ff8c4ebd17d3ff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of external URI heuristics and link farm indicators confirms the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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 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 https://inwebjor.ru/uplcv?utm_term=wwe+2k19+mobile+game+download+apk PDF link annotation
    • http://s13cf5ef.alojamientovirtual.com/ropalaboralbarata.com/userfiles/file/45253957587.pdfIn PDF document text
    • http://zaiger.ru/img/file/58603319286.pdfIn PDF document text
    • https://ietc-oman.com/userfiles/files/99206511568.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161408046c78dd---26111528036.pdfIn PDF document text
    • http://myapartment.de/web/editor/files/11992368936.pdfIn PDF document text
    • http://propertiesforrent.com/userfiles/file///mirijoxavuravudoji.pdfIn PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/161472f2f28305---lenetivarone.pdfIn PDF document text
    • https://darkoyunpin.com/calisma2/files/uploads/jodunoxebamutife.pdfIn PDF document text
    • http://robwalker.net/fckupload/file/84729914436.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/92558765744.pdfIn PDF document text
    • http://sportingclubalbinia.eu/userfiles/files/bosijelunifow.pdfIn PDF document text
    • https://cfi-registration.amyhalter.com/buzzboxgift/img/userfiles/files/senigad.pdfIn PDF document text
    • https://samsunyapi.com/userfiles/files/24154439804.pdfIn PDF document text
    • http://detaycopymatbaa.com/userfiles/file/zoromazekajemilugexuvat.pdfIn PDF document text
    • https://asiahealthcaredentalcentre.com/ckfinder/userfiles/files/83059749463.pdfIn PDF document text
    • http://abacusnancy.com/userfiles/file/74400818219.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/73163490180.pdfIn PDF document text
    • https://graveyards-fuj.ae/userfiles/files/93571345631.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/ba348a2126a7030f9084d477a7f0d859/34109279879.pdfIn PDF document text
    • http://qdsenfeng.com/data/files/mojasem.pdfIn PDF document text
    • http://vucert.vn/uploads/files/31871974731.pdfIn PDF document text
    • http://daithanhnam.com/upload/files/46008827496.pdfIn PDF document text
    • https://pastijptoto.com/contents/files/17174427299.pdfIn PDF document text
    • http://cafehinglung.com/uploads/files/jagodejogujumiz.pdfIn PDF document text
    • 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_off0000d909.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD909 17696 bytes
SHA-256: 0ef3c0028ef31627aabc57173071e6dbbf9801ad21edaa78dc7e73bc8d181926
font_01_sfnt_off00010663.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10663 11020 bytes
SHA-256: 4cbca8efcb829c7bb056f293f9a6384dde18de65cad2076e42191829aaa7772f
font_02_sfnt_off00011fb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1