Malicious PDF — malware analysis report

Static analysis result for SHA-256 84f98c45f1959c41…

MALICIOUS

PDF

86.5 KB Created: 2021-09-07 04:11:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ebd7d32b923ed07d08a200c4d067599d SHA-1: 00ffb3b1ea04aecc032d93c96b8d5741f7e59122 SHA-256: 84f98c45f1959c41d400257fb74538ce70c22f488635b412bdc81fe0fbbb425e
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to domains associated with compromised CMS uploads or disposable hosting, indicating a link farm or SEO spamming operation. The ML classifier also flagged this PDF as malicious with high confidence. No scripts were extracted, and the document body was unreadable, limiting further analysis of specific user-facing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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 http://alibabashipping.com/userfiles/file/59289593334.pdf In PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/160e84b1df1cb2---pogivenojidedoz.pdfIn PDF document text
    • https://palcev.ru/userfiles/file/91934989821.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/s7s6g8k82ao9mqljg2nqre3q52/17349440710.pdfIn PDF document text
    • http://genarchi.com/data/temp/file/5804265698.pdfIn PDF document text
    • http://opuspoint.com/ckfinder/userfiles/files/94137186219.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/tne90k0cmuv7838caies43sk5k/rufuv.pdfIn PDF document text
    • https://guruamardaspublicschool.com/userfiles/files/69874885411.pdfIn PDF document text
    • https://vrindaindia.com/php/joseph/uploads/file/masuzi.pdfIn PDF document text
    • https://evergreencans.com/userfiles/file/20644231884.pdfIn PDF document text
    • https://szabobuszrendeles.hu/files/files/91159826874.pdfIn PDF document text
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160ba8b084171d---nutazuroxi.pdfIn PDF document text
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/9054bfe37289615c33c927ef5d136b5f/jakugaki.pdfIn PDF document text
    • http://iqlacpro.vn/emotive/upload/files/mikajufomokawamuwu.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/43b0ee98e0d4b6fd173578d1154be053/21591580843.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/25d38dcc42d56178613c73c5202c76e1/gawagafetegoruzem.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/ddb3341533d9abd0c9aabaf868892f3c/61702154955.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/41ku54cmnbosekt3ucm7pbned3/mawajunokufeludumerodok.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080b11f56e97---19419349955.pdfIn PDF document text
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/2835ef6d3918378ad1582d82dff4c342/kasosifajogupolepirojuxew.pdfIn PDF document text
    • https://diedacorporation.net/freesiafiles/file/zaxemipagexilozejinu.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ab52516d9c---51937431980.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/bguhrmji865n67q68mm8srgaee/90982086953.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=python+pdf+writer+examplePDF 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_off0000ebec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBEC 18444 bytes
SHA-256: b1dcc41ef1df87dfffdb2e5c296572113462830a11c81c98262de34475ac5ae7
font_01_sfnt_off00011bc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BC8 10896 bytes
SHA-256: f5cf6f3c00354676b4153092e8072a0ccd5b3d8c032a0e230b72beaf1894b67f
font_02_sfnt_off000134e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1