Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b0c820e8f1cdead…

MALICIOUS

PDF

86.1 KB Created: 2021-09-22 13:49:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 90b33a4d0407da7d51357882ea86ded1 SHA-1: 70b31df2fe6719c2ff3aafb91ad15d22c22528e3 SHA-256: 9b0c820e8f1cdead59f5568dda824f7343a4455e09ac05450d269d2eb150a6ea
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to PDF files hosted on compromised CMS platforms. These links are likely used for SEO poisoning or to lure users into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://ketchas.ru/uplcv?utm_term=what+is+the+best+casting+app+for+android PDF link annotation
    • http://pomodorolennep.de/gfx/userfiles/files/44348193178.pdfIn PDF document text
    • http://baheth24aqari.com/ckfinder/userfiles/files/55486727598.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/0e0dfd5cd00766ccdcaebe0c2da1b2df/ragitutukemawomasetojob.pdfIn PDF document text
    • http://jmyhship.com/uploadfile/files/vodalodal.pdfIn PDF document text
    • http://medeeatour.ro/mm/file/zajinizoteteku.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161376d2fb048c---97208564468.pdfIn PDF document text
    • http://loaamtran.com/files/usersfiles/files/dizipedak.pdfIn PDF document text
    • https://rjpexport.com/files/87186001230.pdfIn PDF document text
    • https://rux-thai.com/ckfinder/userfiles/files/xududatu.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/t8k9ihh2ec47u6oslsa6rqffv0/45889422973.pdfIn PDF document text
    • http://yizhu580.com/ckfinder/userfiles/files/pagijemenexigej.pdfIn PDF document text
    • http://jungam21.com/upfiles/file/1631047770.pdfIn PDF document text
    • http://tangneylaw.com/admin/images/file/duberaluzutamilesizefo.pdfIn PDF document text
    • https://sunpower.lv/ckfinder/userfiles/files/dibawujakibivik.pdfIn PDF document text
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/91254945839.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/161485c6c79b19---14791897780.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/16143844920926---14560777214.pdfIn PDF document text
    • https://ksdc.in/userfiles/file/sumagujikifixolekife.pdfIn PDF document text
    • https://5703n1n6999-6a55.com/contents/files/57671762498.pdfIn PDF document text
    • http://jump360.co/upload/files/20210922162450.pdfIn PDF document text
    • https://hoangvan.vn/wp-content/uploads/files/47300310458.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/c15ad8d1701fd6467ae9c10f89812495/povodi.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///donujexoregipuz.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_off0000ea27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA27 10988 bytes
SHA-256: ff4516328b445c8b9ebc045c9caebb0cc35440b058877962d85d7ae8b88bc551
font_01_sfnt_off0001033a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1033A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011b4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B4C 18056 bytes
SHA-256: fe73c59fce1987a36fc2e113fb1d044e6accefde33eb3280f7d72941def4f236