Malicious PDF — malware analysis report

Static analysis result for SHA-256 c91a808982901b72…

MALICIOUS

PDF

75.0 KB Created: 2021-09-04 12:04:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 3eef7c12aa86d69eb33405cffc31fd7b SHA-1: debe50baadd84bc3663500598f7b75dd0abae5b3 SHA-256: c91a808982901b729b96b3d67c307c6b328a2fc70a62b123d8fa71565df2e666
156 Risk Score

Malware Insights

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

The file was identified as malicious by a ML classifier and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to various domains, some of which are hosted on compromised or disposable infrastructure. This pattern is commonly used to distribute phishing content or redirect users to exploit kits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9939

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://zonweringbelgie.nl/ckfinder/userfiles/files/88960292687.pdf In PDF document text
    • http://ahcxdq.com/uploads/file/211022274950.pdfIn PDF document text
    • http://mistral-paints.cz/userfiles/files/91710630311.pdfIn PDF document text
    • http://pantryscan.com/123cars/imagefck/file/94792541551.pdfIn PDF document text
    • https://viboot.com/ckfinder/userfiles/files/78875798934.pdfIn PDF document text
    • http://inciboya.com/resimler/site/files/zekubowiparajof.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce18df1992---52427417517.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/2b4143954812585a0783728074645eca/11221838266.pdfIn PDF document text
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/df3e53e9f30a0e5aafc9b6bd100283f5/lirevawobegudafe.pdfIn PDF document text
    • https://chamsocmuihong.com/wp-content/plugins/super-forms/uploads/php/files/3mb0lgfb0r8in0b803rojtngp8/26060937566.pdfIn PDF document text
    • http://tvoirostov.ru/ckfinder/userfiles/files/takagumagetalobe.pdfIn PDF document text
    • http://www.syrahresources.com.au/application/third_party/ckfinder/userfiles/files/63848932762.pdfIn PDF document text
    • http://czytamzezrozumieniem.pl/userfiles/file/21890167597.pdfIn PDF document text
    • http://ux-school.ru/files/files/fukegilamosaf.pdfIn PDF document text
    • https://www.oalysa.cz/ckfinder/userfiles/files/jukiledusiginologaleb.pdfIn PDF document text
    • https://www.bakirkoytemsilcisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d10bb6c0b1---26690804515.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc5a845450---lofunetunafasefakoxexogun.pdfIn PDF document text
    • http://pomocnaukowa.net/Upload/file/49864556095.pdfIn PDF document text
    • http://vestmorecapital.com/images/epost/wutobudalinubunet.pdfIn PDF document text
    • http://fandimnarodaku.cz/upload/file/2627493286.pdfIn PDF document text
    • http://xn--80aaffebba2apgigwiiececnggk9e4k.xn--p1ai/pict/file/jobabadafedujepekizeju.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/xipotawad.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/2cb373d23e505aed3efc10d6b453cebb/mowerugimekumalakilunax.pdfIn PDF document text
    • http://wjvanderheidedienstverlening.nl/uploads/file/86730445849.pdfIn PDF document text
    • https://kcharp.com/ckfinder/userfiles/files/larewafar.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=energy+bar+chart+worksheetPDF link annotation
    • http://e1pl2.nazwa.pl/busy/fotki/file/54758400559.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_off0000bf81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF81 10784 bytes
SHA-256: f9b251f5460775561c0dd789b0560625e22ffe9326bbab8e49e16224555ff2fb
font_01_sfnt_off0000d86d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD86D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f07f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF07F 17340 bytes
SHA-256: c2393f8e48672d8a2cc40ab5cf904135150daf9943b73170478cf8aaa2992e93