Malicious PDF — malware analysis report

Static analysis result for SHA-256 35bd5d50bb1c3bd8…

MALICIOUS

PDF

95.5 KB Created: 2021-07-22 13:07:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: eafe3d31f208c314e4d527f6b1c996d8 SHA-1: 4d532362cdb25ca280a0a9dcf5f1fd12f96c6323 SHA-256: 35bd5d50bb1c3bd89209b8b740098c30eee5a887cb411033f79faf22f8e18c0b
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised CMS upload storage, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of multiple links on compromised WordPress sites, specifically within formcraft plugin uploads, points towards a common distribution tactic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607ec71f749ee---8477907108.pdf In PDF document text
    • http://aarogyamedico.com/userfiles/file/92321590643.pdfIn PDF document text
    • http://circuitvietnamcambodge.com/hinhanh/file/lubenokomisan.pdfIn PDF document text
    • http://stolizstekla.ru/userfiles/file/52758920110.pdfIn PDF document text
    • http://fotografoenricogiampieri.it/userfiles/files/17930039512.pdfIn PDF document text
    • http://vinhomeshaiphong.net/app/webroot/img/files/sasebedamumixidotididivi.pdfIn PDF document text
    • http://kco.su/userfiles/file/6916391303.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca1e71e1a3---89223444465.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba6462d569---sorijaz.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c95b6f6fec1---fananivamap.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bba589d0bad---87408254570.pdfIn PDF document text
    • http://ucity68.com/clients/e/ea/ea220da86df44fb0ae3b7c8e8295ccc1/File/fogulizewu.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160c52cdcbdbe8---nopovozaz.pdfIn PDF document text
    • http://bigdoughpizza.com/uploads/files/vowuwumaluseg.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/e817ea0821f308d0a31ae75221de1f38/16740058938.pdfIn PDF document text
    • https://biocoils.com/img/file/76269269410.pdfIn PDF document text
    • https://lifetides.ca/cambridge/uploads/files/farisirupatavav.pdfIn PDF document text
    • https://scavilecis.it/userfiles/file/48188423234.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb357e8038---49695603905.pdfIn PDF document text
    • https://prosegik.com/wp-content/plugins/super-forms/uploads/php/files/b6014b89bf5d48f9016783e1b1fd39e2/bodidonukidudakav.pdfIn PDF document text
    • http://abnicum.com/files/file/xulojulu.pdfIn PDF document text
    • http://neo-net.info/giganet/files/file/20463954400.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=static+equilibrium+multiple+choice+questionsPDF 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_off0001106a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1106A 11100 bytes
SHA-256: 0c00325315bc919a7d030231ca3f2dadf2200a73c6f20c8397bf9c85153463fc
font_01_sfnt_off000129d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129D3 17464 bytes
SHA-256: 44123954207da5899156d32070904573406d2486632e333db595e0575aebd439
font_02_sfnt_off000157bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x157BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1