Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c53a994d0d74321…

MALICIOUS

PDF

82.2 KB Created: 2021-09-08 09:47:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 4df4256f786552dc199ac36568474505 SHA-1: 1d07ea4a1b50c6f80a37943bc7f65a03e8d7d473 SHA-256: 8c53a994d0d74321ab3cbc37acd761a9f0c394a81dab86478b73cd61bfb76ea8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to potentially compromised websites or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this, indicating the PDF is used as a link farm to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://garglob.ru/uplcv?utm_term=hound+of+baskerville+full+story+pdf PDF link annotation
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094219848aa0---59790521319.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/2j0fhl3ae9bdt9g1gj59a8un4b/kenonejuwulogowerarogolu.pdfIn PDF document text
    • http://patp1ryb.ru/media/file/vavibusaxefav.pdfIn PDF document text
    • http://nawooelcs.com/upload/userfiles/2021/07/files/210723191451.pdfIn PDF document text
    • https://www.justgym.co.za/wp-content/plugins/super-forms/uploads/php/files/e56e8ev52opk61v5ntjhm2kdda/nasunowap.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/xejafitebarimutofiv.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afda9f39225---8680950905.pdfIn PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/nspnt5btj210d7rb2c9jtfqu9f/taxitigirojafulok.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/f6be117c5e08b7783a9139e7909a815e/3173124055.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce3150b71d---laxuvezeko.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160ad8ba306b62---lovimi.pdfIn PDF document text
    • http://myphamlulanjina.com/upload/files/60736538681.pdfIn PDF document text
    • http://bptramptour.pl/files/file/rivanetufewazokataz.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/160821f50d0d36---tepagujalutiregavesi.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/pogigosexu.pdfIn PDF document text
    • https://hirurgija.me//files/53090641283.pdfIn PDF document text
    • http://attlas.center/userfiles/file/mowodozokunut.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1608522f37d233---78135237609.pdfIn PDF document text
    • http://nriloan.jctoursandtravels.in/files/79515495923.pdfIn PDF document text
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072c2d9be180---naroxa.pdfIn PDF document text
    • https://aadharshilaschool.org/userfiles/file/xofarerisavirusobuxukobu.pdfIn PDF document text
    • http://krakow4you.pl/krakow/files/dujuruzapumamewixemiza.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/wopuniwumijanegaduvik.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_off0000ddcf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDCF 16848 bytes
SHA-256: 8d57c5582d8322335b6a8842f8dc8954ddbc4381e3115e7189d72955b0a08e16
font_01_sfnt_off000109b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109B2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000121c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121C9 10996 bytes
SHA-256: aba867f14a89a671029f007909223fcc3f93008830c38dd82fd1fca080ff9617