Malicious PDF — malware analysis report

Static analysis result for SHA-256 6dda1442cef65ea1…

MALICIOUS

PDF

73.9 KB Created: 2021-09-24 12:27:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 4cf033ddb5d97334ba601b4cb669c5c5 SHA-1: 3ea86625a9a169ed54565b0dbfd3dbcd661b6dd9 SHA-256: 6dda1442cef65ea1c8b847afa7434afdfecf1f816f1ba623d2d1daf961693659
126 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 a link farm hosted on disposable domains, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The presence of external URIs and the link farm structure points towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9901

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://kemnhapkhau.com/upload/files/bavatojanadip.pdf In PDF document text
    • http://electric-kernbichler.at/vifelu.pdfIn PDF document text
    • http://cascad-trans.ru/files/vozapapowimevel.pdfIn PDF document text
    • https://flardochform.se/userfiles/file/59888477392.pdfIn PDF document text
    • http://sportingfoundation.com/uploads/file/8557448210.pdfIn PDF document text
    • http://villaelen.it/userfiles/files/98664150637.pdfIn PDF document text
    • http://labonguyenhoang.com/img-chamthi/files/87714142125.pdfIn PDF document text
    • http://vanharteyoga.nl/uploads/files/ruvorolifaxoga.pdfIn PDF document text
    • https://gres-k.cat/userfiles/file/wakufixajowikuvorenatif.pdfIn PDF document text
    • https://wfca-czech.cz/temp/userfiles/files/39400504093.pdfIn PDF document text
    • https://ferropula.hr/files/29168211257.pdfIn PDF document text
    • http://vdadanang.vn/app/webroot/assets/files/kewefalajole.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/161331a65b3ff4---pawabutuxakigorobopabi.pdfIn PDF document text
    • http://datacomsystems.cz/userfiles/file/fataxe.pdfIn PDF document text
    • http://aurora-c.jp/files/files/ratazubobinakep.pdfIn PDF document text
    • https://deltagroup.bg/uploads/file/rolarof.pdfIn PDF document text
    • http://chapaconoticias.com/assets/ckfinder/core/connector/php/uploads/files/mujijafu.pdfIn PDF document text
    • https://xn--b8qxb801j.tw/upload/files/36847775875.pdfIn PDF document text
    • https://ra7a7p-h3ba7.com/contents/files/83864446648.pdfIn PDF document text
    • https://madspot.dk/ckfinder/userfiles/files/80283835359.pdfIn PDF document text
    • http://oawebserver.com/piceditor/file/20366180853.pdfIn PDF document text
    • http://delta-serwis.pl/pliki/18360524353.pdfIn PDF document text
    • http://webbuilders.com/files/file/34746890206.pdfIn PDF document text
    • http://xn--b1adbbbaeqjtsflbfms0e.xn--p1ai/pict/file/buzejuxabogujetatuvixexom.pdfIn PDF document text
    • http://bangdientunhk.com/upload/files/vimofij.pdfIn PDF document text
    • https://nergizleryapi.com/image/files/37792173288.pdfIn PDF document text
    • http://twgo8.com/uploads/base/files/202109031348407709.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=downloadable+apps+for+androidPDF 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_off0000be76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE76 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d68d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD68D 10620 bytes
SHA-256: 794d0305fc5f25cc8cc28f9b82d46b404ba04100aaf42b4badf66a3153565aa9
font_02_sfnt_off0000eeb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEB7 16880 bytes
SHA-256: c6615722d7b5ef6a077547aa1a62dd163e47682d99decc86be421448b70d8ae5