Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4761ba37c08597d…

MALICIOUS

PDF

79.3 KB Created: 2021-08-29 09:26:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 9716bedb2120d8f5b872708521bfee46 SHA-1: 92cb71792e112c03ee9c7254879f227f9d3aaaf3 SHA-256: c4761ba37c08597d16200fbb3facde9d7851861195021d0ff21d209f3a048f90
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://udmvdpo.ru/images/files/falenilodikarageko.pdf In PDF document text
    • http://kangs78.com/clients/66216/File/voxojusovaparasasifipazo.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16099ace400361---taxagibupimivewo.pdfIn PDF document text
    • https://houstoncoinshow.org/FCKeditor/file/wofoxobaguweperav.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160872d3e65b19---gutododimetenozozukavovi.pdfIn PDF document text
    • http://www.libroparlatolions.it/backoffice/ckfinder/userfiles/files/xizogojunerudeni.pdfIn PDF document text
    • https://sambelteri.com/contents//files/zofesabofamomesupuzofide.pdfIn PDF document text
    • http://youngthisyear.com/ckfinder/userfiles/files/gapowunobetu.pdfIn PDF document text
    • http://ofipapel.org//ckfinder/userfiles/files/18777057037.pdfIn PDF document text
    • http://www.pataniforum.com/admin/jquery/ckfinder/userfiles/files/gineniduberojiri.pdfIn PDF document text
    • https://parlagame.com/calisma2/files/uploads/31945336191.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608823ec9cea3---14169869101.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1611e87272651a---pavodogikin.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bcb026a2914---nikubiv.pdfIn PDF document text
    • https://grand-forge.ru/wp-content/plugins/super-forms/uploads/php/files/c0f9352d1881de07c6d0f6a6330c5f07/29443309523.pdfIn PDF document text
    • https://krantiservice.com/ckfinder/userfiles/files/82916629840.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/vopuzo.pdfIn PDF document text
    • https://gancza-yacht.pl/userfiles/file/butajewube.pdfIn PDF document text
    • https://bodymart.in/ckfinder/userfiles/files/354387459.pdfIn PDF document text
    • https://abeess.com/userfiles/file/gubotifixumarisawegulov.pdfIn PDF document text
    • http://mamnonsaokhue.vn/app/webroot/files/ckfinder/files/64308307575.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/58218691698.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606e3b048f1b2---pamapuk.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/c5a5591b90010dc2838c9b490388de37/jesujigarumuk.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0a8c4069a2---23766147097.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160a6a952ceba7---zezekojumowetulujimo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=subordinating+conjunctions+and+commasPDF 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_off0000d2a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2A2 16804 bytes
SHA-256: c550a970110012964cae05b500c15b863fe74ef9e338b2e3f3da1a7e24ffe822
font_01_sfnt_off0000fdea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDEA 10980 bytes
SHA-256: 6398af82bd38d90d1912bd287855c8ba902dd42055af8f65a7be99546685dcb5
font_02_sfnt_off0001171e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1171E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1