Malicious PDF — malware analysis report

Static analysis result for SHA-256 f537f8499af337d7…

MALICIOUS

PDF

89.1 KB Created: 2021-06-29 13:34:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b4eb4fd69f708d0d98fc472a0f5754e8 SHA-1: 2ba1d34d5b960293fbd19d78383b403c51ae98ca SHA-256: f537f8499af337d7050ac65cf9f8aabfa68180dbee912d3568703412ff07f6e3
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs that point to compromised WordPress sites, suggesting it functions as a link farm. These links are likely intended to lure users to phishing pages or download further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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 https://cructi.ru/uplcv?utm_term=funny+brain+teasers+with+answers+for+kids
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16094b27a159d7---wolubasipepoxiwaz.pdf
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160b486acd1d47---96969956605.pdf
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16090c4501067c---62715739182.pdf
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/d44f53c2c6d4eefa585ad50653258c64/wadetunibijux.pdf
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096f47cc183e---71585378487.pdf
    • https://pensiuneavalentina.ro/app/webroot/file/2499264042.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b290951b0a3---gozobeke.pdf
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/0b01501fcab50b161f9e0d6322b79f6d/19314467898.pdf
    • http://ylphs.com/ckfinder/userfiles/files/66444186293.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4af6b8a9d2---65573872741.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/avn988hcof9u35rc404on8csa5/gasenubitazofolowemes.pdf
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/vl39m2de6pmaugvsetndm7c4i7/ritewazubedi.pdf
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/33fa395bd1b7d0894fda23951e00b5d4/75796055978.pdf
    • https://ajitcoatings.com/uploads/kogebararu.pdf
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/04b25b7a27254171c48775a1356ed628/27458920909.pdf
    • http://zrdb-drogbud.pl/Upload/file/29164547307.pdf
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160866dc024601---puwekotowaxigupumut.pdf
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082b67336b2c---3674053294.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160720e0653293---fimajuwemujifizifazax.pdf
    • http://4x4autok.hu/userfiles/files/2878793832.pdf
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607c4946c2efd---2841619590.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160717b2bb63af---riwesikikudugasaxaxem.pdf
    • http://www.chiringuitomediterraneo.com/ckfinder/userfiles/files/72877223484.pdf
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093f52e4cccd---93643778066.pdf
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607c8a58e16fe---tusapinaxubonawetege.pdf
    • http://osteriadelcampanile.com/userfiles/files/nolimuwaxidofowexukakus.pdf
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1c439a0d07---2562752650.pdf
    • http://eko-inwest.eu/upload/file/67133453906.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f889.bin
f609dff7d3846233cde45a7bb422254e9f2c28a49e1699b76d4730c7e054aaf7
pdf-font-stream PDF embedded font (sfnt) at offset 0xF889 10912 bytes
font_01_sfnt_off000111d6.bin
5b769160d28eccf1b6b210bb5e5a4276b5f2499c9b1227be27df6e0ae80efd7b
pdf-font-stream PDF embedded font (sfnt) at offset 0x111D6 16556 bytes
font_02_sfnt_off00013ca3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13CA3 16792 bytes