Malicious PDF — malware analysis report

Static analysis result for SHA-256 733fd36380b7ec9b…

MALICIOUS

PDF

81.1 KB Created: 2021-09-17 22:56:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 2688fea059e64020144127d81a5d4e0b SHA-1: 694de4e32f9d8ae3bfe061a2a836f9cae4d90ad4 SHA-256: 733fd36380b7ec9b3db4108ea4ca735ad695428130917d0ab23f0f2856a2378f
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Numerous heuristics indicate it functions as a link farm, directing users to various compromised or disposable hosting sites. The embedded URLs and the PDF structure strongly suggest an attempt to lure users to external malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pistant.ru/uplcv?utm_term=turn+off+ads+miui+12 PDF link annotation
    • http://esllearningbydesign.com/app/webroot/files/file/49754683650.pdfIn PDF document text
    • http://mimarathi.live/assets/ckfinder/core/connector/php/uploads/files/buruve.pdfIn PDF document text
    • https://f2h63c2.ip4secure.net/upload/files/funetuwudok.pdfIn PDF document text
    • https://khanoomhoteli.com/basefile/khanoomhotelicom/files/70039395918.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/51479884552.pdfIn PDF document text
    • https://milorem-service.ru/userfiles/file/gawepipominefefog.pdfIn PDF document text
    • http://lifecontinues.ru/images/files/bazajelotesafix.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/16de8a783a3452726ba8d155a96dcfac/94138979269.pdfIn PDF document text
    • http://jlicentral.com/images/authors/file/wolozagomugow.pdfIn PDF document text
    • http://chono.mn/uploads/userfiles/files/44627776113.pdfIn PDF document text
    • https://galerieportelouise.be/userfiles/files/49061414210.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/16141771898106---4373155164.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/ropidak.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139e689c4b76---jowovipizagexekadinawekef.pdfIn PDF document text
    • http://alotercuman.com/ckfinder/userfiles/files/judaritexul.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/5dcbaf3308e9d07ecdd27bc1fe07fb72/tiloxisavopofoboji.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/161419c32ba179---89034906401.pdfIn PDF document text
    • http://tangiahoang.com/skinkorea/Images_upload/files/2525241001.pdfIn PDF document text
    • https://huanghecables.com/d/files/74731460029.pdfIn PDF document text
    • http://siripanyalamphun.com/user_img/files/betuguli.pdfIn PDF document text
    • http://akvatoria.by/UserFiles/files/43044204613.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_off0000d9ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9CA 10472 bytes
SHA-256: 091eeee6f94df2c4456c802574abd35e5440273d504486e61975755abca6fdb3
font_01_sfnt_off0000f19a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF19A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000109ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109AC 17588 bytes
SHA-256: 7e87f9487e615748ce88796cc83c2ebcea8593fed750e7414f8a0d901c41ce48