Malicious PDF — malware analysis report

Static analysis result for SHA-256 946805d37de4e8e9…

MALICIOUS

PDF

78.3 KB Created: 2021-09-21 12:56:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: be0f6bbf13d9966e778fe2febabc319a SHA-1: da569c4f04a5606ef44711168615d5bc544593c7 SHA-256: 946805d37de4e8e9452d5f9f01570a12fac5c0d2d785475c6db9ecc569167be7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The embedded URLs and the nature of the heuristics point towards an attempt to trick users into downloading potentially harmful files under the guise of firmware updates.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://synerhu.ru/uplcv?utm_term=android+tablet+firmware+update+tool+download PDF link annotation
    • https://jungleflightchiangmai.jungle-flight.com/Uploads/files/tamasafevosezoxenow.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/03ef9e024294ff3891b29e29c6aa912e/13670351220.pdfIn PDF document text
    • http://caytrong.vn/Images_upload/files/95566074011.pdfIn PDF document text
    • http://recviem.ru/img/upload/tepexiruduxax.pdfIn PDF document text
    • http://staractivecollection.com/resimler/site/files/wokiledukuvozuwor.pdfIn PDF document text
    • http://origo.ws/userfiles/file/bavazolakemowufofifizewo.pdfIn PDF document text
    • https://niboparis.com/upload/fckeditor/files/wubepupe.pdfIn PDF document text
    • http://pincesorvarshop.hu/editor_up/44036143270.pdfIn PDF document text
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161416b9221b8b---83805241069.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135460f833c4---98551691139.pdfIn PDF document text
    • https://gamepinleri.net/calisma2/files/uploads/zadelirosutuviwog.pdfIn PDF document text
    • https://www.libyamonitor.com/sites/all/libraries/ckfinder/userfiles/files/nogesewamabarazo.pdfIn PDF document text
    • http://www.ettermanenterprises.com/ckfinder/userfiles/files/87258694483.pdfIn PDF document text
    • http://zaiger.ru/img/file/vumirosezulaj.pdfIn PDF document text
    • https://virtrade.gr/userfiles_lybo/file/koraxajezudanumuvizijo.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613e85b97515b---fexazegamabapirig.pdfIn PDF document text
    • https://jamurgoreng.net/contents/files/kejinarelok.pdfIn PDF document text
    • http://ozhelalikram.de/resimler/files/ruzira.pdfIn PDF document text
    • https://eminenceconstruction.ca/viking1/uploads/files/99528990637.pdfIn PDF document text
    • http://chuaphucluong.com/uploads/image/files/namogux.pdfIn PDF document text
    • http://taiwanquinoafamily.com/shopadmin/upload/files/16242321837.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_off0000ccda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCDA 18100 bytes
SHA-256: f68a70fd4a8316b7eb8bba108c64527c5701d5efce94fc818575c9aac02777ed
font_01_sfnt_off0000fb5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB5B 10800 bytes
SHA-256: 4a1d8b29003295fd890710d57de87717b198cc69c4dfea2dfb13383c27bcc162
font_02_sfnt_off0001140b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1140B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1