Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1e8c5f1bccea952…

MALICIOUS

PDF

88.5 KB Created: 2021-09-10 10:14:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 5086f812ea5b64459d033ef90bb389a6 SHA-1: 03a7de2a87376bb5a5c85b80e56f9b26ddf79b13 SHA-256: d1e8c5f1bccea9526fbb648f283b32a3c5cfa8e3b22386a4a82d5bdd6953a6f3
126 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains a large number of embedded URLs, many pointing to disposable domains, suggesting it functions as a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicates a malicious intent to redirect users to potentially harmful content. While no scripts were extracted, the sheer volume and nature of the URLs point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://essaidafm.com/uploads/FCK_files/file/71433472595.pdf In PDF document text
    • http://mopron.ru/upload/files/15655258804.pdfIn PDF document text
    • http://dintainoodle.com/uploads/files/93640525252.pdfIn PDF document text
    • https://thingstodobahrain.net/ckfinder/userfiles/files/39069102708.pdfIn PDF document text
    • http://kprmk.pl/userfiles/file/jubobolovolowarorexitu.pdfIn PDF document text
    • http://vekosgroup.ru/userfiles/file/tizojarelafitimopusezep.pdfIn PDF document text
    • https://asiarsolutions.com/userfiles/file/zekirojasebuzu.pdfIn PDF document text
    • https://hw-power.com/uploads/ckfiles/files/613ad4892ece8.pdfIn PDF document text
    • http://ilsogno-bomboniere.com/userfiles/files/66234428002.pdfIn PDF document text
    • http://www.europesolidaire.eu/userfiles/files/wotelepowipu.pdfIn PDF document text
    • https://tlproduct.com/userfiles/file/furegifesowofefo.pdfIn PDF document text
    • http://ildungrice.com/fileupload/fckeditor/file/solelusobifiv.pdfIn PDF document text
    • http://manuale.aziendasulweb.it/userfiles/files/86557775192.pdfIn PDF document text
    • http://mcenterdk.ru/fck_editor_files/files/78167525148.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161315b6572557---786479277.pdfIn PDF document text
    • https://almudenafernandez.co/ckfinder/userfiles/Files/joluzut.pdfIn PDF document text
    • https://zebcom.in/userfiles/file/femulefataxugisomavupok.pdfIn PDF document text
    • https://sentinels.ro/userfiles/file/tebatujemabugotore.pdfIn PDF document text
    • https://totalsewa.com/userfiles/file/paberabositoxunawif.pdfIn PDF document text
    • https://fobh.net/userfiles/files/tisurafevupi.pdfIn PDF document text
    • http://kargo-box.com/uploads/files/gosaxidizeraxepikug.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/161305c0ac3873---monuve.pdfIn PDF document text
    • https://leonardscopysystems.com/home/leonards/public_html/ckfinder/userfiles/files/78621155441.pdfIn PDF document text
    • http://handgun.ee/media/file/24553154816.pdfIn PDF document text
    • http://tjsyjdq.com/v15/Upload/file/202192819289604.pdfIn PDF document text
    • http://www.yemany.com/yemfiles/files/jagutagivawutizadimelo.pdfIn PDF document text
    • http://sor1310.com/userfiles/file/12130687653.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=jenkins+install+android+sdkPDF 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_off0000f3f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010c0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C0A 10324 bytes
SHA-256: 656624d5da6713577fa0f728aea8ed3e43a9820ab33fd8625292638651f5df3a
font_02_sfnt_off00012375.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12375 18308 bytes
SHA-256: 8474c9f342b8d59e3779fdd6ea35e85f7c80b68bb22a9fc04fb083f58f4bf393