Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e731beb9b7ed176…

MALICIOUS

PDF

94.7 KB Created: 2021-08-18 11:46:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 92261435da0952d924ba8b2980aeceee SHA-1: dcfdd0a7a65b33ca158a17922ed327781a8091a5 SHA-256: 8e731beb9b7ed1769c5f9cb22f2bd8620a7cca87631d5ed417fbbdecba620a5a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of links, many pointing to disposable domains or compromised CMS upload directories, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the nature of the link farm and the detection results point towards a malicious document, potentially leveraging embedded JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://quangcaosms.org/media/ftp/file/41900750825.pdf In PDF document text
    • http://donghotam.com/luutru/files/75645721316.pdfIn PDF document text
    • http://dientrotiendathc.com/media/ftp/file/33992764023.pdfIn PDF document text
    • http://519pf.com/userfiles/files/vujofidigetumibuwal.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/ad9e6510d9c09e003b13a8e347c3b640/97517775717.pdfIn PDF document text
    • http://studiomontironi.eu/userfiles/files/86724582830.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/06a8db9e5ca4d7315c168d4457af4f80/lemurunuxawugelerumid.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/6mdbi1g23csamiou3tqlrm5h15/kagojokojixame.pdfIn PDF document text
    • http://gerd-pollak.de/userfiles/file/59425417785.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074729632d4e---96366990925.pdfIn PDF document text
    • http://teplospectr.ru/images/files/44256845835.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609dac6fbf2e9---59371732945.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16095b16936025---vunetotemim.pdfIn PDF document text
    • http://yokosohk.com/files/fckfiles/file/firuz.pdfIn PDF document text
    • http://impex-italia.it/userfiles/files/12050374051.pdfIn PDF document text
    • https://aravlicraft.com/cmsCart//upload/file/79300037119.pdfIn PDF document text
    • https://www.siemers-deutschmann.de/wp-content/plugins/super-forms/uploads/php/files/fgeh7gk8nd8g436mci5d0o2kkg/mojuzebefexi.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/8f36920d7c17fee290f7190d184775aa/xededow.pdfIn PDF document text
    • http://mxm-hosting.nl/img/editor/file/pijixevifelowotuxawapux.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607f73baaf7e7---gokelumigadaxonin.pdfIn PDF document text
    • https://cleaner.pl/userfiles/file/6328167608.pdfIn PDF document text
    • http://brenna-ski.pl/userfiles/file/tepunusuwatowozapotig.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cbba58d1cab---5455720459.pdfIn PDF document text
    • http://olimpic.hu/ckfinder/userfiles/files/31914867170.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a7c995d9fa2---nudoxodizaxuki.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=indian+actress+age+below+20+in+2020PDF 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_off00010ed9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ED9 17116 bytes
SHA-256: 1f36b86465f6ca10da45e85fd1f6dd7cf7d3bc2012028798c5c3ca7d2c71b949
font_01_sfnt_off00013b38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B38 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001534f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1534F 10964 bytes
SHA-256: 9b593c44df3cb251791f2f3eb4edebc1974632ccc7d818555346f5ac01a5dcf0