Malicious PDF — malware analysis report

Static analysis result for SHA-256 875aa7328eaea512…

MALICIOUS

PDF

80.8 KB Created: 2021-07-20 21:52:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 1337b066c5681e97973dab8054335595 SHA-1: 7bd9428dc734b1c6354c09e28faf4ae01efb7d78 SHA-256: 875aa7328eaea512cd22625d78ebb9e0a1495439507edb97d5d95e0932c479fd
156 Risk Score

Malware Insights

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

The PDF file contains numerous links pointing to compromised WordPress upload directories, suggesting it is part of a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The document body is heavily obfuscated and unreadable, preventing a more detailed analysis of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://oumkua.com/userfiles/file/77356068981.pdf In PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ac440c4f342---miperopariloj.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2819a0287---75291377362.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/epmbvg6sh6079patmgr6tqqbhn/50423503216.pdfIn PDF document text
    • https://healthcareadvisorsgroup.com/wp-content/plugins/super-forms/uploads/php/files/tedc8hs2l0in2adj5vb5d9bn30/joduvedaguzetabes.pdfIn PDF document text
    • https://oceanflowerhotel.com/uploads/image/files/zosakup.pdfIn PDF document text
    • https://aljuboori.com/userfiles/files/jitodozoferujuwexisisuse.pdfIn PDF document text
    • https://www.northwoodmedical.ca/wp-content/plugins/super-forms/uploads/php/files/59ou7t4iqvavrqvlvvfo2cr5b1/tofajobomijijen.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160744d4ac6954---wakovozurorij.pdfIn PDF document text
    • https://1877painters.com/FCKeditor/file/60299167974.pdfIn PDF document text
    • http://cherryontop.pl/upload/fotki/file/vekoponedirizogosomozifo.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/fc41149e866c771a47e6ec702b9912c3/12954055155.pdfIn PDF document text
    • http://phrabat.net/UserFiles/File/nesakivano.pdfIn PDF document text
    • http://builderall.info/userfiles/file/22735160838.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-6-10/20210610192026499131.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ceab931e740---56363177962.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ee725c31085---golovabivezirogi.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160b5476585ee0---lefebabozujone.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160b56f1d63773---6149788319.pdfIn PDF document text
    • https://agenciaboom.com/wp-content/plugins/super-forms/uploads/php/files/k9p4vtidnmlasqng6dp7sb36b6/tugufewigusufomotokerur.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/3nmvm8itv99fbvtuheg7urdevh/75606142691.pdfIn PDF document text
    • http://sochistandart.com/ckfinder/userfiles/files/nutixivorazusuze.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/672a8012a31020bca9de0e2a8cb7962b/73751024865.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160c9b457c19dc---2515604625.pdfIn PDF document text
    • http://vejwun.cz/images/25957739045.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/1504f9b554236f43ab72fbdadfc85e04/51047290057.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=to+be+barredPDF 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_off0000dc49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC49 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f45b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF45B 17024 bytes
SHA-256: cf95fbc3a29beaadc7b11f4b2999987a584530e21a30b798650f8a5f9c00ec30
font_02_sfnt_off0001208b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1208B 9836 bytes
SHA-256: d916b589c994a5c345eb6830c34727daee60ad063803b46649e0de10fcf29bc4