Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a23acf01f49e6ba…

MALICIOUS

PDF

77.3 KB Created: 2021-06-17 22:54:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 1147e0426c09ee633a2f3196e83feb78 SHA-1: 30aeb86dc65b5cc51f0469f7440f8ec094e75be1 SHA-256: 8a23acf01f49e6bafe415db3391c607288a5f4574b7a589e8a3157bd63aa599b
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to various domains, many of which appear to be compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO spam. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, but no executable scripts were found.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://aiswaryamatrimonials.com/fck_uploads/file/rarulujoregowapikil.pdf In PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/855e5698b325002c21a9385636a3e896/60859658680.pdfIn PDF document text
    • http://calisnt.com/uploads/files/xajexaxerukokozeputalad.pdfIn PDF document text
    • http://93564497.com/userfiles/verobovujazugozij.pdfIn PDF document text
    • http://ascensionchina.com/userfiles/file/18291619067.pdfIn PDF document text
    • http://abimobiliare.pl/pliki/File/fuxawebozadakevelezizigej.pdfIn PDF document text
    • https://atkarisuli.hu/userfiles/file/gexeselowilede.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/c40d66159adf1d4a481903921023045d/88941968320.pdfIn PDF document text
    • https://ukdirectremovals.com/wp-content/plugins/super-forms/uploads/php/files/cde8a35d1a3638c29182eabb1760ccd3/66859017588.pdfIn PDF document text
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac227c996f1---kodinivezopojo.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/2d8cgl3a2389kpobtctfo6mcgd/kupajuterab.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/e97117f2a2da54d471847cd0dd772a7c/4452702133.pdfIn PDF document text
    • http://dichvugiayphep.net/hinhanh_fckeditor/file/91112886817.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/57144acb5206b8ceccb7e0482e378e56/lebidumevekepozopuzolokid.pdfIn PDF document text
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/848f07bce222944226c9213549000f48/bagutetijetu.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/846d6881b2139be8a395481b390f190a/sesufenelavuvuv.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1d7e78907---xugojipodeninisij.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=example+of+psychomotor+learningPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f070.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF070 5556 bytes
SHA-256: 59fd973dc2578f3ff4eb5337eca1982004f6b19fe7982c88c8a25045997da5a2
font_01_sfnt_off00010340.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10340 11076 bytes
SHA-256: af115cc67ffcc8e4afd9aa21076b44bd70d1d0f530c22730578ca96d95a3c148