Malicious PDF — malware analysis report

Static analysis result for SHA-256 4327845f0c274681…

MALICIOUS

PDF

76.7 KB Created: 2021-06-28 19:49:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 0c7964399a971533e470b58642b2a768 SHA-1: 2179d9d7058669ecaa9079a3718a74719d132669 SHA-256: 4327845f0c274681ead53be38da7c57bf3517fc2f7e39e20fbcec5f85943305f
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file contains embedded JavaScript and a large number of external URLs, many of which point to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The embedded JavaScript and link farm structure suggest an attempt to redirect the user to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://laborke.ru/uplcv?utm_term=myacht+houseboats+for+sale PDF link annotation
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/d217eefe818d2a6d7f3d9f804f63219a/92774353921.pdfIn PDF document text
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a2f5d8c7ba3---boxoxenix.pdfIn PDF document text
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/04hcji3ieiaa5ls5glqeu9t9fq/topaxopokasawafomose.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/2697abc54cdf8b1127cd9e31ede1706a/sasexigezebano.pdfIn PDF document text
    • http://olimpic.hu/ckfinder/userfiles/files/wunizimufosebosebow.pdfIn PDF document text
    • http://evergreendentistryva.com/app/webroot/js/ckfinder/userfiles/files/83705012398.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/2c8f762d113dedfcb629d26240cb6dbd/79872786393.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081bf3287d76---badivasalagideminedufubit.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608feb26606ad---30337902646.pdfIn PDF document text
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/d23c2ded2d23d1120b150ad027326b89/foxatitogovanu.pdfIn PDF document text
    • http://nitexprofi.cz/userfiles/file/82484319980.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16093a5102b4c6---41949897233.pdfIn PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/7534e8a51ab0d5394c9f88b68026b4ac/befuxarijipup.pdfIn PDF document text
    • https://leo-translate.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160832aa6657e1---90630386091.pdfIn PDF document text
    • https://mls.lighting/wp-content/plugins/super-forms/uploads/php/files/291845f41e4fffedac8b9a955db4fb3d/niradimupuporipatevat.pdfIn PDF document text
    • https://mebelihome.ru/upload_picture/jiwubagorij.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/c45fd6801491c2136d5a5544315c66a9/10990482092.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a7d1de6b907---38809921701.pdfIn PDF document text
    • http://smflow.in/admin/uploads/file/nigibemijixobidi.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a205db7f25---75897795617.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/e0ad5f1f7aa14f707bc2b77f1b18d7b0/35706484201.pdfIn PDF document text
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/09c68b0f7bf829066905e9baddc33f17/laganiwarusododorikaf.pdfIn PDF document text
    • http://musorcentrum.hu/files/article/file/39930468624.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/ed4e71dc66e157c8425585c8e1508d7b/nenato.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160821842a0f71---zumoxexizasipenopa.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160bf57af5bb48---79678874206.pdfIn PDF document text
    • 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_off0000c866.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC866 16976 bytes
SHA-256: 2b3f0777d178c1d38608fd6e919b44ad9f59422d8645e25d2a3132ce7fa6d8c9
font_01_sfnt_off0000f4ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ce1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CE1 10584 bytes
SHA-256: 91c4f5ab34c0907d5c20141a5758a4a10af7f7e6be986d81ea5f76729d5c2b3f