Malicious PDF — malware analysis report

Static analysis result for SHA-256 537d2a89b3d49ca4…

MALICIOUS

PDF

83.3 KB Created: 2021-09-02 09:46:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 34cba731bd7445d72e828f947b1045dd SHA-1: 96b5224cf96f1d0e77111dedee4ec60ee8cd29ba SHA-256: 537d2a89b3d49ca47df26c18fd2f87d1bb9f32f311ca294fdfece28866367417
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to compromised WordPress upload storage, indicating a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the PDF structure and URL patterns are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/0d685269d6d8779cd9c6a544a4cbf398/puguxilunuzetusemonor.pdf In PDF document text
    • http://www.propper-droppers.nl/files/file/40912956787.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1608735fee1edb---vofexuvurewekabuwe.pdfIn PDF document text
    • http://crm333.com/documentos/file/76767368981.pdfIn PDF document text
    • http://hanasushimenifee.com/uploads/files/48451733442.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/38161873038.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/1609a176c27c9e---xuxunenosupeguluw.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/160f0b4e34ea8f---58523630312.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160925ae7dcec6---xevidafuvanixupude.pdfIn PDF document text
    • https://digireg.nu/upload/jijisimudo.pdfIn PDF document text
    • http://antropolog.ru/userfiles/file/22549668296.pdfIn PDF document text
    • https://netpage.info/userfiles/file/35136974906.pdfIn PDF document text
    • https://vinatech.com/userfiles/file/74110024881.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/99dd55a206303ba7c58591c20a586c56/vefevos.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f8c64738a46---koruwuwilagivifusozori.pdfIn PDF document text
    • https://sgcaregiver.org/contents/files/76512348582.pdfIn PDF document text
    • http://www.ez4parcel.net/upfile/files/2021/08/03/85067285648.pdfIn PDF document text
    • http://endustriyelkiralama.com/wp-content/plugins/super-forms/uploads/php/files/8e8tqrgqvk7hfmgojknq46nnot/nitolidufol.pdfIn PDF document text
    • http://firegallery.ru/img/upload/mudedepubawexit.pdfIn PDF document text
    • https://hamasataccessories.com/userfiles/files/9425258739.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/13659656865.pdfIn PDF document text
    • http://marsalanoleggio.it/userfiles/files/12123722829.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b528e8efd1c---56869235019.pdfIn PDF document text
    • http://asiavent.com/UserFiles/file///55209140186.pdfIn PDF document text
    • http://arohitourandtravels.com/userfiles/file/relevodu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=reasons+why+seriesPDF 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_off0000e3b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3B2 10304 bytes
SHA-256: 933719558f2c866497a35a4f0234ef9376260af839290c7b5790ce1cf5281629
font_01_sfnt_off0000faea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAEA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000112fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112FC 17332 bytes
SHA-256: 746e04f516b0814abd5e8d12be466669172d624d7f1856f339be87c4ce9ae4ef