Malicious PDF — malware analysis report

Static analysis result for SHA-256 b91e67bcbc50ab07…

MALICIOUS

PDF

78.2 KB Created: 2021-09-04 19:18:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 1b583588974cfc4847122b9092e38138 SHA-1: a53d3887ab547acc7c937feb4e57f6795c251b8c SHA-256: b91e67bcbc50ab07095c397689805c4ac8f0ac939700d9ee7f822049bcf098e3
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document functions as a link farm, directing users to multiple distinct hosts, some of which are hosted on compromised WordPress sites. The presence of numerous URLs, many pointing to PDF files on various domains, strongly suggests an attempt to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://asiavent.com/UserFiles/file///valepa.pdf In PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1608177f4e1792---3576514196.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa48ccc4738---3495132412.pdfIn PDF document text
    • https://korzayithalat.com/spot/admin/fckeditor/userfiles/file/2924008917.pdfIn PDF document text
    • http://cosmosimpex.com/app/webroot/ckfinder/userfiles/files/muvelijonilarigepekavij.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/lte22mt5lgllgg8f8nlnjq4gu5/80452824604.pdfIn PDF document text
    • https://igruppe.no/ckfinder/userfiles//files/nitalofariliwilad.pdfIn PDF document text
    • https://footballsod.com/images/ck-uploads/files/xojovivir.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///11594434534.pdfIn PDF document text
    • http://world-housing.jp/ckfinder/userfiles/files/3499820528.pdfIn PDF document text
    • https://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/ace8d90539cafc08ecf9c6a49847721b/zagekelexevogitim.pdfIn PDF document text
    • https://e-uchebnici.com/img/file/16877367574.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/20e98447cd5ba97a3912f275252dcf6f/kumemasepur.pdfIn PDF document text
    • http://hoadon-dientu.net/images/files/nasoxoponedop.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/ed6203d1adc8a82494659fb0ede8d777/76605524542.pdfIn PDF document text
    • http://bobhendrix-law.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jozalij.pdfIn PDF document text
    • https://stradatextiles.com/upload/ckfinder/files/diduwowimivoxi.pdfIn PDF document text
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/882328ccf542cc89ef652b44f21e61e9/22409243306.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/debtq1r3qtsglugeucu8lfieh6/56360071810.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1610ecae78f47d---xizajuvagejiwavamuw.pdfIn PDF document text
    • http://olddieselparts.com/ckfinder/userfiles/files/39224014838.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/efec8bff1069155b46f0bba5f6eff9eb/66049357434.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093b1bcc13f6---64277556381.pdfIn PDF document text
    • http://www.propper-droppers.nl/files/file/delalonatinexepuwufowenu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=structure+of+a+virus+%28bacteriophage%29+worksheetPDF 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_off0000c95d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC95D 11324 bytes
SHA-256: a9607b9afab9f77f01a1c4e211684194f7e7793af15965015af1858453ef2b41
font_01_sfnt_off0000e42f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE42F 17908 bytes
SHA-256: 07d2e0d5ca195fbb5766e1c0f3931aee54232c2574ab92f8ac1e35f265ccc386
font_02_sfnt_off000112e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1