Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b81c71e449a7782…

MALICIOUS

PDF

79.0 KB Created: 2021-09-23 07:34:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 912e780ad19b29de3a260107713a6727 SHA-1: bcf3a24f869195290f2e8e93a200df0b02b0adba SHA-256: 9b81c71e449a7782d45e5b66b23969219975ffecb8ee29fc4307ece84552525d
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, flagged by ML classifiers and ClamAV as malicious. It functions as a link farm, directing users to numerous external PDF files hosted on various domains, likely for SEO poisoning or to distribute further malware. The presence of embedded JavaScript suggests an attempt to execute malicious code within the user's browser or PDF reader.

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://purevdavaa.mn/uploads/ckfinder/files/jomire.pdf In PDF document text
    • http://criollo-cocoa.com/userfiles/file/bujeroranagativikoditulun.pdfIn PDF document text
    • https://textolinguisticsolutions.com/upload/editor/file/muxujosi.pdfIn PDF document text
    • http://beergolfers.com/blog/images/file/gopum.pdfIn PDF document text
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/94d1de5cda6aa4c3fefa524b44415ce7/renivokurutefogez.pdfIn PDF document text
    • https://powerliteaac.com/userfiles/file/17806664532.pdfIn PDF document text
    • http://naturalfurnish.com/userfiles/file/63664052328.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/7f13822d94b10fe7e1ed25f41a4a881e/vunoriporoxejaluteluse.pdfIn PDF document text
    • http://www.leads-bd.org/app/webroot/js/ckfinder/userfiles/files/nofeluronipuzewukokizew.pdfIn PDF document text
    • http://studioingegneramato.com/userfiles/files/94690056684.pdfIn PDF document text
    • http://www.pes.edu.mn/ckfinder/userfiles/files/noxazutigeduvo.pdfIn PDF document text
    • http://synergyproperty.com/images/files/44499633440.pdfIn PDF document text
    • https://almentispharma.com/ckfinder/userfiles/files/fomifagubowifekivuxugisiz.pdfIn PDF document text
    • https://fetogram.ir/images/upload/files/marakipeximijewokamozo.pdfIn PDF document text
    • http://hotelbellevuepalermo.com/userfiles/files/24365703197.pdfIn PDF document text
    • http://5m-tti.com/uploads/image/files/12170880031.pdfIn PDF document text
    • http://ksiclubbiz.ksiclub.org/svnprojects/DHD/Source/images/files/57327771030.pdfIn PDF document text
    • http://byecook.com/ckupload/files/famigasadedavejajiwane.pdfIn PDF document text
    • http://aeusjtu.pretty-match.com/upload/files/napujorurupegurirotijup.pdfIn PDF document text
    • http://timecraftz.com/userfiles/file/tujafavovi.pdfIn PDF document text
    • http://uteambio.com/upload/files/51728515979.pdfIn PDF document text
    • http://bradhelferlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/67066221152.pdfIn PDF document text
    • http://grandviewgroupresort.com/upload/files/96471694464.pdfIn PDF document text
    • http://avalon-essenzen.at/userfiles/file/ruxebifodorapowolusa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=das+kapital+in+marathi+pdfPDF 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_off0000c4f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4F0 10604 bytes
SHA-256: eef436fcb5b592122040d7501be4536d6a943ef06ea73b3134985d8573d04c02
font_01_sfnt_off0000dce9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCE9 22248 bytes
SHA-256: 4fca9eca86805448bc705bb9ea8313820b3d20c4bcb3ffc32e72cba112159f18
font_02_sfnt_off0001164d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1164D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1