Malicious PDF — malware analysis report

Static analysis result for SHA-256 3cdfcaed06ae6a6b…

MALICIOUS

PDF

86.5 KB Created: 2021-09-16 03:27:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 54f1dcab6e251d02befbfa9f2d88e4bf SHA-1: 53c66a12e3f5ff02033844fde3794b4f52b3a546 SHA-256: 3cdfcaed06ae6a6b0f722be9961dce93aaeaaf78d1bd30862fdcb11d53866315
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ML classifiers and ClamAV, indicating a phishing or trojan payload. Numerous heuristics identified it as a link farm pointing to various disposable or compromised domains, suggesting an attempt to redirect users to malicious content. The embedded URLs are the primary indicators of compromise, likely leading to further stages of an attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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=best+email+client+for+android+tablets PDF link annotation
    • http://yuli-china.ru/d/files/74776117787.pdfIn PDF document text
    • http://worldtile.net/jangheung/userfiles/file/99194295491.pdfIn PDF document text
    • https://ka-base.no/images_content/file/75699165873.pdfIn PDF document text
    • http://emaaravm.net/upload/files/10263343029.pdfIn PDF document text
    • http://dsacare.com/admin/uploads/file/nebumu.pdfIn PDF document text
    • http://studio-castiglioni.com/userfiles/files/64088719192.pdfIn PDF document text
    • http://cerritos.songhakbbq.com/uploads/files/26216943676.pdfIn PDF document text
    • http://clairerolo.com/userfiles/file/51452771396.pdfIn PDF document text
    • http://yingtailong.com/upload/file/210904072429323417s68kkcbfcfue.pdfIn PDF document text
    • https://thucphamtruongxanh.com/Upload/files/52851128566.pdfIn PDF document text
    • https://szabobuszberles.hu/files/files/wimofovukomebudepudo.pdfIn PDF document text
    • https://khmernative-rice.com/userfiles/file/57750626749.pdfIn PDF document text
    • https://hoatuoi360.vn/uploads/files/56734894455.pdfIn PDF document text
    • https://kolegium.inaheart.org/upload/files/rofewiludosozowe.pdfIn PDF document text
    • https://bk.knu.ac.kr/ckfinder/userfiles/files/pesenexatosufojutesuma.pdfIn PDF document text
    • http://jiab.net/userData/board/file/41445080618.pdfIn PDF document text
    • http://gesht.ru/admin/ckfinder/userfiles/files/32269711095.pdfIn PDF document text
    • http://champagne-marc-chauvet.com/images/files/vozutoteb.pdfIn PDF document text
    • http://dongsimkindergarten.com/upload/files/57565151825.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/77a16831e047a9d737b880271ce2cfd1/69716510051.pdfIn PDF document text
    • https://roofmed.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161413e9f46656---pajaniguvikewosijapov.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/qvlvg5shns4fbn6tncit7g0ld6/sewadowafeludidudejakaw.pdfIn PDF document text
    • https://interno-kazan.ru/upload/files/bibiparijasebifizevigonam.pdfIn PDF document text
    • http://swotaweb.com/img/upload/file/74891720927.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_off0000ecd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECD5 10828 bytes
SHA-256: a8b68b078b2bc76cb5376aaf6f1750234e6b82efd788064f214816a9696c88fd
font_01_sfnt_off000105ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105CA 17676 bytes
SHA-256: 843db0ef49ccb938c5bb03a28131c5244d19baca35dd1d62c5204e27bc30f752
font_02_sfnt_off000133ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1