Malicious PDF — malware analysis report

Static analysis result for SHA-256 40817b339bfd52f8…

MALICIOUS

PDF

90.8 KB Created: 2021-10-07 22:23:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d6682ea76e054dcd5fca61126be8621e SHA-1: 9428dafa7b7d9b8e2f244add4b1dc46feec182ea SHA-256: 40817b339bfd52f81889f9a61948dbd0f8d90f8481667a2198b7c704704582ee
156 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware. The document body is heavily obfuscated and appears to be generated content rather than user-readable text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://nomylo.ru/uplcv?utm_term=convert+mp4+to+dvd+online+free
    • http://thaicockstar.com/ckfinder/userfiles/files/93529603634.pdf
    • https://accu-split.com/userfiles/files/vowogafufum.pdf
    • http://year-c.com/upload_fck/file/2021-9-3/20210903113237746164.pdf
    • https://wrd13.com/force/file/wilarekavume.pdf
    • http://konditsionery-odincovo.ru/upload_picture/file/tafoxodirubo.pdf
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140e382a11a5---84434462045.pdf
    • https://cuisinescartier.ca/upload/editor/file/91069200071.pdf
    • http://felixefontesadvogados.com.br/ckfinder/userfiles/files/36597410966.pdf
    • http://murito.fr/ckfinder/userfiles/files/jugibomepexuxuke.pdf
    • http://maurovalleferroarchitetto.eu/userfiles/files/zemadimenixetubo.pdf
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615614e67bd8d---neketoxijuxalagegiwovi.pdf
    • http://bastola.org/userfiles/file/55884696279.pdf
    • http://thekitchendesignstudio.org/uploads/files/zutebamijikaxuf.pdf
    • http://lnv-cnc.com/userfiles/file/113506237.pdf
    • https://agrocare.ro/ckfinder/userfiles/files/fimopi.pdf
    • https://coevent.ru/upload/files/dimisejikuwitusu.pdf
    • https://ismet.com.br/ckfinder/userfiles/files/magetokedoloj.pdf
    • http://benetalent.com/upload/files/91924992639.pdf
    • https://thebillionbottom.com/business_school/uploads/file/51196733177.pdf
    • https://villanakarin.com/userfiles/files/loliworuninanunireviz.pdf
    • http://bephoangdung.vn/uploads/ckfinder/files/kugutalonusodigokosip.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615881d0697a8---93814510624.pdf
    • http://edeins.com/userfiles/file/fidaraxe.pdf
    • http://knowleangling.co.uk/ckfinder/userfiles/files/gepuninelawadawupujixi.pdf
    • http://scuolascifondocortinadolomiti.it/userfiles/files/72383637067.pdf
    • http://cyclad.org/UserFiles/file/molubatopidokabamubapew.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ff00.bin
6c8f01172fe22065025211bb624bfcce3a63958a1736209c9075a67a9d78499c
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF00 18096 bytes
font_01_sfnt_off00012d5a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12D5A 16792 bytes
font_02_sfnt_off00014571.bin
98b93edf4e0699edb0da201cc573b3ce6a12e63bfb695de34f72f46ba6e0c27d
pdf-font-stream PDF embedded font (sfnt) at offset 0x14571 10504 bytes