Malicious PDF — malware analysis report

Static analysis result for SHA-256 21a03a7635441b89…

MALICIOUS

PDF

79.6 KB Created: 2021-09-02 14:19:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fd8c5dfe622a6a83aebe3b31f965734d SHA-1: ce37406b3abba10ae2f0d328848fa89de58b7b57 SHA-256: 21a03a7635441b89cfbcf8387ad136d539a78d4148bc9b4bcf5d50b1fac229f7
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. Heuristics indicate it functions as a link farm, pointing to multiple compromised CMS upload directories and disposable hosting. The embedded URLs suggest an attempt to direct users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://akproauto.com/nbloom/fckuploads/file/losifesawamumujubiraruxef.pdf
    • http://deurenhanger.nl/userfiles/file/11478679543.pdf
    • http://hangtatmj.com/userfiles/tewodopejus.pdf
    • https://taksis.lv/taksis/userfiles/file/nelexegudulewo.pdf
    • https://penzionradvanice.cz/res/file/tobesaxu.pdf
    • http://box8websites.com/ckfinder/userfiles/files/14137598438.pdf
    • http://juniorsmagazine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c5f74120ec---jajigojekugodawax.pdf
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ed5e0e0cd3f---bepaburoxolobotutebujone.pdf
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078061e8aca2---kodovevutoxegib.pdf
    • http://debandhelder.nl/ckfinder/userfiles/files/34379544590.pdf
    • http://excitechem.com/userfiles/file/18363653012.pdf
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/392866e1aecc5b15104eac040e3a0e02/71746132251.pdf
    • https://0286869143.com/editor_images/files/zufepoporuxaje.pdf
    • https://ccveg.org/wp-content/plugins/super-forms/uploads/php/files/7t0u44drm2thvl1h1qio1h87bq/molidigufoxugitenuromole.pdf
    • https://houstoncoinshow.org/FCKeditor/file/98916612957.pdf
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16099c31e44376---guleno.pdf
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aabeef49456---62902355529.pdf
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/vsj8qr8iqabvp51jo5703duu42/32903205815.pdf
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f6ebda9129d---23721387905.pdf
    • https://szallas-karpatalja.net/upload/28729358650.pdf
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/2326201735006aa1edb827f321918f0d/55140138857.pdf
    • http://sozopolihills.com/userfiles/file/13971812820.pdf
    • https://geniodelweb.com/file/3236786276.pdf
    • https://kfmaccounting.com/webroot/img/content/files/18170645007.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=algebra+finding+slope+worksheets
    • 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_off0000d22f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD22F 16792 bytes
font_01_sfnt_off0000ea46.bin
a8e885944131ab71bd65909def7892933e46095e042605fe55618fe427c82c19
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA46 11076 bytes
font_02_sfnt_off000103a3.bin
125305eb3eab0372eea6b138208f3919333d90ee39ce7f490803bf9b2b037fd6
pdf-font-stream PDF embedded font (sfnt) at offset 0x103A3 17424 bytes