Malicious PDF — malware analysis report

Static analysis result for SHA-256 52d4a214c6f0883c…

MALICIOUS

PDF

155.3 KB Created: 2021-06-04 09:08:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: 4fa5a821619a630b29f92d37db2d5280 SHA-1: 82fcb9fc9b1f3544cac00056bc419f0d3734efc4 SHA-256: 52d4a214c6f0883c1125a2443c9459779ea2fe5520cba5424caf0329c11bacc4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://chcial.ru/uplcv?utm_term=toonami+my+hero+academia+saison+4+replay PDF link annotation
    • http://www.franklinwebdesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd1b01a907---molebu.pdfIn PDF document text
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/43d17b509caba2b4ac54a0ac24d6ab5a/gonate.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1607f322435e4c---ziruba.pdfIn PDF document text
    • https://www.perfumista.co.uk/wp-content/plugins/super-forms/uploads/php/files/a5533bc7856fdd77c2e80a2d62473d8f/tedavadasu.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dfb3446803---44686147329.pdfIn PDF document text
    • https://www.freshstartdigitalmarketing.com/wp-content/plugins/super-forms/uploads/php/files/74ab47bc550e56b060fa0069a49b9e87/rumipevegilupe.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b77336ada08---49204148898.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/df208bb427edb1463f630a28ccc4ed4f/mejetuvaza.pdfIn PDF document text
    • https://athensviptour.com/wp-content/plugins/super-forms/uploads/php/files/386a03a0dcfbacbc7d32904406908f76/32345164485.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d4ae89569b---kuguru.pdfIn PDF document text
    • http://thehawthornnyc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d028d957ee---gorabulikepupazoj.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/d48ad6761e0e917fc41556d311688337/9651627856.pdfIn PDF document text
    • http://fygl.net/uploads/file/281227225582.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609effa89442e---gusij.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_002_off000133af.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x133AF 80656 bytes
SHA-256: 4bd96d1be637a005de98d33f8cdac5e32ff5651823f6f6e3287a502beefde7e9
font_01_sfnt_off000225cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x225CC 5452 bytes
SHA-256: e93459a955ab743e010d599311f7e32d0ba3c451b795f0589b49639999181b0a
font_02_sfnt_off0002383a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2383A 11728 bytes
SHA-256: 4737ce34c22d8772cde699fd7737b6467138792b0017d4870b090081a79466fb