Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5820c3a54cb3f56…

MALICIOUS

PDF

72.6 KB Created: 2021-09-11 22:36:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 79ae345585ba341aa2da3a10b1c72c83 SHA-1: c451194c7f406d8884a68be7aa0dff972848fb4c SHA-256: b5820c3a54cb3f561ca03996cfafcf7198eaa52bd3cbef75237ccf2645ecf23a
96 Risk Score

Malware Insights

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

The PDF file contains numerous links, many of which point to compromised WordPress sites. The ML classifier strongly indicates maliciousness, and the structure suggests a link farm designed to manipulate search engine results or redirect users to potentially harmful content. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/fecf3b361a0c17e1dc784e279b63320c/23468459042.pdf In PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613be98ecfad7---69268821954.pdfIn PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/86811ac24855d8f326a8ba228458bf58/vumaxirefozeninopafobem.pdfIn PDF document text
    • https://bibliotheque-des-arts.com/ckfinder/userfiles/files/79560351071.pdfIn PDF document text
    • https://bimetoor.com/basefile/bimetoorir/files/wibisonofe.pdfIn PDF document text
    • https://rireenfrance.com/images/upload/files/lisanapaluli.pdfIn PDF document text
    • http://weddingdove.tw/uploads/files/202109042344283864.pdfIn PDF document text
    • http://aceonlinementors.com/userfiles/file/sinulutofowibemomakusom.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/mqq4l4q9kg9b97fgtv1udkh5k7/kosifotajavamuvatanegur.pdfIn PDF document text
    • http://come2menorca.com/images/file/51440364920.pdfIn PDF document text
    • http://aybar-gallery.com/userfiles/files/tamafamidekasalanibeka.pdfIn PDF document text
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/363a6f755075fd9515aa3aa26fd0e3ca/pomujelokod.pdfIn PDF document text
    • http://ifap.it/images/file/14230637876.pdfIn PDF document text
    • https://rakowka.pl/userfiles/file/wujijomaritukojotitolota.pdfIn PDF document text
    • http://bukhatirhomes.com/userfiles/file/nikepuzazux.pdfIn PDF document text
    • https://thehouseproduction.net/file/melewivomo.pdfIn PDF document text
    • http://vimbark.sk/editor_uploads/files/15084864344.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/afdddad35becfadce6c15c1dc7062b60/taguzuporudokefewalovisam.pdfIn PDF document text
    • http://hennel.hu/sources/elemek/file/bitanupomasuwoxidimuvusif.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613656090c52a---65008956529.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613440fb5298b---ruvekosaxirumizudupedazi.pdfIn PDF document text
    • https://sikdercollegeofpharmacy.com/scp/ckfinder/uploads/userfiles/files/7386456554.pdfIn PDF document text
    • http://mastrodibaglio.it/userfiles/files/5283964123.pdfIn PDF document text
    • http://jiangsutravel.kr/userfiles/files/20210909_230837.pdfIn PDF document text
    • https://seedcambodia.org/htdocs/cljr/data/files/rorefafesazojewafo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=hay+day+bot+free+downloadPDF 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_off0000b9df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9DF 16344 bytes
SHA-256: 505bf06be4f32f8aed8cea2357d556e781c289d721599867839732512bfc1fb6
font_01_sfnt_off0000e3b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3B9 10416 bytes
SHA-256: c9fcd4a8535432fb066eae12b473806e0b2cb605fa477ff37176ece0d4370ae7
font_02_sfnt_off0000fb7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB7C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1