Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb7938bd569a3b6f…

MALICIOUS

PDF

81.3 KB Created: 2021-09-10 17:21:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: fe836e0486492d47e49a7e3c1b00b0df SHA-1: bc6d0e6270dd0773cf2d8c1eb54fcee4fb74218c SHA-256: fb7938bd569a3b6fb3ae2ed82cc69d89020943f063b0276a4d7646c826730864
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised or disposable domains, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but likely serving as a container for the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://huntic.ru/uplcv?utm_term=how+to+take+screenshot+galaxy+s9 PDF link annotation
    • https://biogenetixpharma.com/ci/userfiles/files/47818578898.pdfIn PDF document text
    • http://scsychem.com/upload/files/zilukewugev.pdfIn PDF document text
    • http://wittymall.com/multimedia/userfiles/file/lobovajumamab.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/fujakirixesodo.pdfIn PDF document text
    • https://www.drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16132311955bb7---80328326116.pdfIn PDF document text
    • http://tangiahoang.com/skinkorea/Images_upload/files/mupugogitakejasugewaxiguf.pdfIn PDF document text
    • https://eniedu.com/data/file/20210905195145.pdfIn PDF document text
    • http://www.sauminandy.com/fckimages/file/zebisonufuxurutoxuradi.pdfIn PDF document text
    • http://partner-support.net/user_data/userfiles/files/sozevamisezokotuw.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/161330f8ba8103---40519119490.pdfIn PDF document text
    • http://industrialdevices.in/uploads/68377801195.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/2n37cvatc3203sse3udtn1ep12/37846733842.pdfIn PDF document text
    • http://xn--80aiddhbkcq5bcaz.xn--p1ai/upload/files/88762715887.pdfIn PDF document text
    • https://apartmani-mestrovic-krk.hr/files/lafudewoserekifaxe.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/81a6967149e2484b711caf9acae1371f/4300052588.pdfIn PDF document text
    • http://winteringlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jeluwezumisima.pdfIn PDF document text
    • http://self119.net/upload/userfiles/2021/09/files/210904220557.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131cf5d5be94---33392886000.pdfIn PDF document text
    • http://ituor.ir/basefile/chartermeinfo/files/53268377630.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ae38da898e---68897790874.pdfIn PDF document text
    • https://yuanfuconstruction.com/ckfinder/upload/files/57444411196.pdfIn PDF document text
    • http://www.badischer-kunstverein.de/ckfinder/userfiles/files/wegodubejawikobavuxoruxid.pdfIn PDF document text
    • http://pnc21.com/files/fckeditor/file/879049196613253c898ad7.pdfIn PDF document text
    • http://thai-apsproducts.com/file_media/file_image/file/pebukerigedozizoje.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/89899924636.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_off0000d8f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8F1 17480 bytes
SHA-256: ce8117caaa959007a7468223c0e39e408c31ef40b903660df946e7c51dce2a51
font_01_sfnt_off00010643.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10643 10968 bytes
SHA-256: 37f64b42d99901b7316c63528e93e8721bd65e0f771040962bcccba37834e3ed
font_02_sfnt_off00011fd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FD4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1