Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9ac7804a321e1d6…

MALICIOUS

PDF

84.6 KB Created: 2021-08-13 09:11:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 7da960f767ae37b543f2a888ca717bc0 SHA-1: e7b66f9ea27a057db9175aba94c80ac5a9fd5661 SHA-256: b9ac7804a321e1d675b4f38d84e18489111c64529ce8008540e1cbf7d1b6c365
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports its malicious intent. The primary goal appears to be directing users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • 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://inwebjor.ru/uplcv?utm_term=kgf+2+tamil+full+movie PDF link annotation
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16079c0c12a2c0---84744757759.pdfIn PDF document text
    • http://cityhelps.org/clients/6/61/61afa7a028a8e04f14432b0fece6f2b0/File/16587727923.pdfIn PDF document text
    • http://turhantur.com/turhantur/files/95381746111.pdfIn PDF document text
    • http://dragonspond.com/uploads/files/93853851304.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e038f107f3---jidopegilekalu.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/16104917540a6a---nejexoko.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c874b59390a---lifilojavamif.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6925fbd7a2---lolilijuribogozowevifis.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608adfadde378---jegagus.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/7935561018.pdfIn PDF document text
    • https://chupwo.com/editor_upload/file/43454851094.pdfIn PDF document text
    • https://chung-pei.com/userfiles/file/tademotag.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/29800590000.pdfIn PDF document text
    • https://taiwancy.com/app/webroot/userfiles/files/6366138447.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610715fbd8210---33401186240.pdfIn PDF document text
    • https://hyundainhapkhau.vn/upload/files/zunetilerazopiz.pdfIn PDF document text
    • http://pastadimatteo.com/ckfinder/userfiles/files/8502011769.pdfIn PDF document text
    • https://acryl-bg.com/userfiles/file/paroremekusoz.pdfIn PDF document text
    • https://khogiaydantuonghanquoc.com/images/news/file/33384861878.pdfIn PDF document text
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/160c4d88f07602---toruduxuvatisawigikositas.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/so4nbu94naf26cibrkrlt6ag94/danukupemoxupegizobi.pdfIn PDF document text
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/cbdd563f16ead57dedac1e0ff79f217e/xakuzebatorewu.pdfIn PDF document text
    • http://evevoyance.fr/adh/.-/file/wepedebulibam.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607df0ac6dffc---94843096720.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_off0000e790.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE790 10460 bytes
SHA-256: 3cac3a88ef371dc3c965be5500277e80ac0a73aa656a65f63a04a1c2f96d707c
font_01_sfnt_off0000ff71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF71 17052 bytes
SHA-256: 89033d8ed3a3528bc8fbb603e678dba577d0c480e666c89bf11d3b9181172d15
font_02_sfnt_off00012ba6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BA6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1