Malicious PDF — malware analysis report

Static analysis result for SHA-256 f389857ed82727ba…

MALICIOUS

PDF

81.8 KB Created: 2021-09-24 11:00:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 34f13d99292f5880212185e4839b2660 SHA-1: 77741da4b2d9fb47ce10b5da2f17e1b664906ad2 SHA-256: f389857ed82727ba9ece2aad78a1e0114e102cd91e2e4a83781b55e7d05f73f0
174 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous links to external PDFs hosted on disposable domains, indicating a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to trick users into downloading further stages of malware. The presence of embedded JavaScript points to its use in exploiting PDF vulnerabilities or delivering malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://allytemp.ru/uplcv?utm_term=anbudai+nenjam+srikala+novel+free+download PDF link annotation
    • http://hnc2.com/userfiles/file/gawokamolemebawogodipib.pdfIn PDF document text
    • http://banhangcongnghe.com/upload/FCK/file/laberixewas.pdfIn PDF document text
    • http://laserbeautymachine.net/d/files/ritabowefobaxidotokidisiz.pdfIn PDF document text
    • http://ubytovna-krumlov.cz/userfiles/file/zozamifudosig.pdfIn PDF document text
    • http://biaikatolikus.hu/files/file/55040320169.pdfIn PDF document text
    • https://alternativecarrepair.nl/userfiles/file/52582645032.pdfIn PDF document text
    • https://penzion-palice.cz/content/pufeniwala.pdfIn PDF document text
    • http://www.39koratmachinery.com/file_upload/files/64876722438.pdfIn PDF document text
    • http://tianlanlawyer.com/filespath/files/20210921173436.pdfIn PDF document text
    • http://3gr-group.com/ci/userfiles/files/bizavelimadupogen.pdfIn PDF document text
    • http://www.jacenter.org/js/ckfinder/userfiles/files/5864248530.pdfIn PDF document text
    • http://cathugo-yachts.de/res/wysiwyg/file/42300974680.pdfIn PDF document text
    • http://casms.org/atts/news-files/file/nikuxixixofemufiwe.pdfIn PDF document text
    • http://vizesblokk.hu/files/file/62345994086.pdfIn PDF document text
    • http://ambulatorioveterinariocigliano.com/userfiles/files/vakuvupujujogipipiladupaz.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614259c68e0a7---komugowi.pdfIn PDF document text
    • http://www.ximangsongthao.com/app/webroot/uploads/files/77375339659.pdfIn PDF document text
    • http://ddaengshop.com/ckupload/files/93873454626.pdfIn PDF document text
    • http://emirates-offshore.com/uploads/image/file/52985195412.pdfIn PDF document text
    • http://dep14kirov.ru/userfiles/file/goluxinukazetikesu.pdfIn PDF document text
    • https://trickapotisk.cz/webpagebuilder/ckfinder/userfiles/files/72057579174.pdfIn PDF document text
    • https://klcmekatronik.com/ckfinder/userfiles/files/61178953434.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130c5bd5c82e---1669484051.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_off0000cd32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD32 23268 bytes
SHA-256: 38d472bfb5b7f09df1f01b536edfafa2d8e5215e830398b3edf3d3157a1d2d59
font_01_sfnt_off000107e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107E1 11012 bytes
SHA-256: a744c5cc031b659fe732b24ecadee7a4948668ba657e4b3aba512b9bceafbd74
font_02_sfnt_off00012179.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12179 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1