Malicious PDF — malware analysis report

Static analysis result for SHA-256 b739f3de207304b4…

MALICIOUS

PDF

76.8 KB Created: 2021-06-25 22:44:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5202a77f950003af2296854177680151 SHA-1: 20c97938360506cf03915067b8959c13d1058bb2 SHA-256: b739f3de207304b48d829847da4f306ec7bfc78c76f540fe2371bb3614d92d9a
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating it's a phishing or trojan PDF. It contains numerous links to external PDFs hosted on compromised or disposable domains, suggesting a link farm designed to distribute malware or lead to phishing sites. The presence of embedded URLs and the overall structure point towards an attempt to trick users into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/98mamue57als4755mtsjitqih4/tosuwokadufu.pdf In PDF document text
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b69cabeb8f---15921079181.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/29188931479.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c8af9343f97---1437661958.pdfIn PDF document text
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/3u9tck890ga1s6vdsfq50ffio0/menanuxenedugoxapedosita.pdfIn PDF document text
    • https://eatorhours.org/e-bussiness/fckimages/file/pesefi.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/b8612cc11c9ba9904b938e21901c95c3/89394055615.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a52e8772fa4---95641760736.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609dc06e00923---winobebune.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f006e9237b---41588315035.pdfIn PDF document text
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/39a5b5dbd1ae92c298f45278e255bdec/xirulukikikegikemilez.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1608c10eba33b5---71609185300.pdfIn PDF document text
    • http://debcopharma.com/userfiles/file/wopadifiduzexukapevilak.pdfIn PDF document text
    • http://alemotta.com/resources/original/file/42165100247.pdfIn PDF document text
    • http://cdmatik.com/uploads/file/35911238387.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609873ae64fda---12396404726.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b1a566b64b---64556194139.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/3f6b323f4eef7a704fea84aaafe04e92/vesekelerajixojawo.pdfIn PDF document text
    • https://actor-conseil.com/files/file/tawomiruparapewupika.pdfIn PDF document text
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/015ba9b3a75c95ee9f2473d76545026a/rabufedexedowazot.pdfIn PDF document text
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b7afcdc32a0---43778770844.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609dbe11dd1c6---jukajuzaxadelejumudarowi.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/1b4131fc7bebaf323d70bebaa44c4afc/guputeboxiwabuzedavojul.pdfIn PDF document text
    • http://mirandatutoringcentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607fee5a42418---93719831486.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1608ac99f8d5a7---42138138579.pdfIn PDF document text
    • https://www.nrlandscapes.co.uk/wp-content/plugins/super-forms/uploads/php/files/4c8e04e6ca035e4895b9c0ba7bc61e11/39090574998.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bf89a20f2d---giwije.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=autocad+2d+basic+drawing+exercisesPDF 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_off0000c83e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC83E 11028 bytes
SHA-256: 52c102eb04751bbba0e3db45cc0688a47d4f7568f49699e164709725228a2ae7
font_01_sfnt_off0000e202.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE202 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fa14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA14 16100 bytes
SHA-256: d451dd9c68ffcb5a59aba6f295283c7a1cf6d61f07de3232099ede616968225a

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