Malicious PDF — malware analysis report

Static analysis result for SHA-256 25a8cdb81fa0aeea…

MALICIOUS

PDF

71.4 KB Created: 2021-09-26 19:04:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 8dd7c973d028900ebc4203566d646b72 SHA-1: 6ae7c7a6e4b1708af14116716b82647f618d41cf SHA-256: 25a8cdb81fa0aeead0b6250b0460123f38e300ef5ff7779449a9c3aa4a37445b
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs, several of which point to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple links on disposable hosting and the use of UTM parameters suggest an attempt to obscure the final destination and potentially leverage SEO for distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://mariautonoleggiomarsala.it/userfiles/files/balaxizebemudada.pdf In PDF document text
    • https://franchise-vietnam.com/app/webroot/img/files/2559091087.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/b9c4137c3c27662e4e154d8d0ce26c77/17338055200.pdfIn PDF document text
    • http://cudicio.it/images/file/23380918419.pdfIn PDF document text
    • https://dubaimotorcycletours.com/uploaded_images/files/33398289916.pdfIn PDF document text
    • https://saunadlaciebie.pl/userfiles/file/85697749003.pdfIn PDF document text
    • http://olgapolyakova.de/files/files/12240656090.pdfIn PDF document text
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142e646351c9---14010278954.pdfIn PDF document text
    • http://avstralianature.ru/ckfinder/userfiles/files/47087252456.pdfIn PDF document text
    • http://ekopaczka.pl/imgbrama/files/66781598519.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/pumuzuvapimuwilatomu.pdfIn PDF document text
    • http://exmar.it/foto_fck/file/85996090806.pdfIn PDF document text
    • http://erodiertechnik-wenzel.de/userfiles/file/sojasudonemubesazixekiz.pdfIn PDF document text
    • https://chorland-dining.com/webroot/editor-uploads/files/47446601485.pdfIn PDF document text
    • https://agroadvanced.com/app/webroot/newsletters/editor/files/6100154306.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/olmvnsins97v97mskf3a48f740/52174223433.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/8rgboqh2ef19qnju9qshmjk5eo/67512671325.pdfIn PDF document text
    • http://jjw-led.com/userfiles/file/vasazupuzosase.pdfIn PDF document text
    • http://www.iciparis.ru/ckfinder/userfiles/files/noxapebem.pdfIn PDF document text
    • http://zzlhlt.com/userfiles/file/LianMeng202109250352354171.pdfIn PDF document text
    • https://cqc-material.com/app/webroot/userfiles/files/kunudobivi.pdfIn PDF document text
    • http://www.tahi.hu/ckfinder/userfiles/files/liforivimupuroduturaj.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161500c367c541---xabikutokonejakegufanives.pdfIn PDF document text
    • https://tvmreza.tv/ckfinder/userfiles/files/4962965184.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=iphone+6s+data+not+workingPDF 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_off0000b46e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB46E 10924 bytes
SHA-256: e15fd488b2abbcd4710c9a0225888564bfbb82611e8aaae33001d556f712f262
font_01_sfnt_off0000cd96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD96 16696 bytes
SHA-256: 3f829e21dda53738832c4862e1d5d7ccbf0965cd27c13ec03e58330ceafbc6a4
font_02_sfnt_off0000f874.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF874 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1