Malicious PDF — malware analysis report

Static analysis result for SHA-256 88e0788d6a6a3e7a…

MALICIOUS

PDF

73.8 KB Created: 2021-09-04 01:18:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 006f673e4aed7fb43ee97e1320bc5833 SHA-1: 4ba059c0dd4ba00877c8b484215fea1c9e273450 SHA-256: 88e0788d6a6a3e7ac652350c8ca0e7ebb6903be673efa954919c58e206b24048
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and links to compromised WordPress upload storage, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://krisoc.ru/uplcv?utm_term=family+and+friends+3+special+edition+student+book+pdf PDF link annotation
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/19tudd8a4a0gqd0r1r4tnt8g30/matilafivizorazolugafopu.pdfIn PDF document text
    • http://innotack.com/userfiles/files/fokejubosoredaro.pdfIn PDF document text
    • https://bhandarisurgical.com/ckfinder/userfiles/files/nemajijoru.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608004c321c06---97580681583.pdfIn PDF document text
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/e8604376aa29b2ec38c513be1ff4c547/5195725674.pdfIn PDF document text
    • http://indyztyle.com/ckfinder/userfiles/files/31780913378.pdfIn PDF document text
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080af2bdf9fb---85252710613.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/f27otdm7f7g3l6iefgqna9v7m4/norureligatobi.pdfIn PDF document text
    • http://com123.vn/uploads/file/gapobotaxo.pdfIn PDF document text
    • https://aymfly.com/aym_image/files/30041754017.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/5eb851968820d7db3142b4ec5d3e8555/zabitazudikibep.pdfIn PDF document text
    • http://austria-ex.com/images/blog//file/mijexazisobabomogep.pdfIn PDF document text
    • http://keyflounge.nl/userfiles/file/3894336371.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093fc44ceb66---556431255.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/b44eb5abf34952fb63033b2f5ff0d081/juzoferasuz.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609334e348c75---4816258314.pdfIn PDF document text
    • http://sten.kr/club/data/userfiles/file/20210809224151.pdfIn PDF document text
    • https://steklo-shik.ru/userfiles/file/wesikowusularuxenonifuv.pdfIn PDF document text
    • http://www.iece.in/userfiles/file/latavupageval.pdfIn PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/95b29e1f098099dd96b11c51b7ce0426/nitogomunevosuzilok.pdfIn PDF document text
    • https://bevillelecomte.ovh/ckfinder/userfiles/files/tevetufotivulafafusafe.pdfIn PDF document text
    • http://m-s-g.ru/userfiles/files/delepamowobepoj.pdfIn PDF document text
    • http://flygarfield.net/userfiles/file/daxiwakoloxeratemilagu.pdfIn PDF document text
    • http://tubietelbar.hu/uploadfile/58552632604.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_off0000bd7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD7A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d591.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD591 11376 bytes
SHA-256: 1f9b10c5f51a4d0cdf7a7226b7dc7d5c4a891d01d2353864c6c76591bb8f3b31
font_02_sfnt_off0000f025.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF025 16208 bytes
SHA-256: 738b16685e1bb8e76b08ddef52b68e4eacf7da4a613d84f8e503a8634d7725aa