Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b6757b9d7605888…

MALICIOUS

PDF

94.4 KB Created: 2021-10-08 01:37:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 0107fb9e31fed4780f88bda008d5101e SHA-1: 4bdfad4f693df4eb9fbded04fa5ac39e33c20d83 SHA-256: 7b6757b9d7605888fe5f6d0407a9d7978a858754f89d54347228dbcc9b059104
126 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm on disposable hosting, with numerous embedded URLs pointing to PDF files. The presence of these characteristics suggests the PDF is likely a lure for phishing or to distribute further malware, aligning with the Spearphishing Attachment technique.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9888

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.prieur-equipement.com/ckfinder/userfiles/files/57373006966.pdf In PDF document text
    • http://imhang.com/fckeditor/userfiles/image/15017876763.pdfIn PDF document text
    • http://iccj.jp/images/uploads/fckeditor/file/12455764828.pdfIn PDF document text
    • http://inruho.ru/ckfinder/userfiles/files/84190175554.pdfIn PDF document text
    • http://brilsports.ro/userfiles/file///29117270676.pdfIn PDF document text
    • https://www.domaine-boussard-chablis.fr/ckfinder/userfiles/files/33114168955.pdfIn PDF document text
    • http://kolbiko.com/images/uploads/file/sazagebotix.pdfIn PDF document text
    • http://sherwoodchambergolf.com/ckfinder/userfiles/files/73058312459.pdfIn PDF document text
    • https://cebrium.ssnn.ro/images/lirejeropiziga.pdfIn PDF document text
    • http://rem-proekt.com/f/file/32105083410.pdfIn PDF document text
    • https://gebzecelik.com/userfiles/file/korupozakipixu.pdfIn PDF document text
    • http://chargooshads.com/images/upload/files/dejasoz.pdfIn PDF document text
    • http://ukrainski-rosyjski.pl/userfiles/file/92045216243.pdfIn PDF document text
    • https://amadesafar.ir/basefile/amadesafarir/files/36768898026.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/32475899631.pdfIn PDF document text
    • http://mobiliteit.nu/files/4873703539.pdfIn PDF document text
    • https://gabconstruction.com/ckfinder/userfiles/files/22390796288.pdfIn PDF document text
    • http://myphamasia.net/upload/files/pilumevotixisozulinupido.pdfIn PDF document text
    • http://zzquansu.cn/d/files/veliloguxigowunojuv.pdfIn PDF document text
    • http://steinbach.casawell.tw/userfiles/file/vetuposomoperowagitetusi.pdfIn PDF document text
    • http://studiofantino.it/userfiles/files/91362220253.pdfIn PDF document text
    • http://tareeapartment.com/user_img/files/pusutinanusibune.pdfIn PDF document text
    • http://cafegreenwichvillage.com/uploads/files/vopiju.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/xasanajafugugefiro.pdfIn PDF document text
    • https://moveo-sport.pl/userfiles/file/53043929123.pdfIn PDF document text
    • http://kernenshepler.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fepitigegemekosijasov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=star+present+perfectPDF 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://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_off00010a18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A18 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001222f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1222F 10292 bytes
SHA-256: 1561a0fa681fc203e963547453817e85721e345961c72401f09e6f726a3b6ec4
font_02_sfnt_off00013976.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13976 19160 bytes
SHA-256: 2ad6f57a7647fb32a642050c47b693834d5012adaed9ac5f3969d4cb7692231d