Malicious PDF — malware analysis report

Static analysis result for SHA-256 de8d35861127bc62…

MALICIOUS

PDF

77.1 KB Created: 2021-05-03 14:26:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 107ab35f24203a19a396ac9b43187f78 SHA-1: 6afd18779dc53291b90f4ee824b5e2163e6365f4 SHA-256: de8d35861127bc62a8c00757c492ee281994cb089cd4cfa35dc8538451549906
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate it functions as a link farm, directing users to compromised websites, specifically noting a link to 'chagatea.ru'. The document body, though heavily obfuscated, contains metadata suggesting it's a formal letter, likely a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/5ef9982be2def8ed8cbc29f5753f05ea/zinifalisuwenebujexigo.pdf In PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082de93043a7---karivalaw.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/a2ad1f0d5145cd0e168118bf83f47917/lesemidewudobija.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3c035ce47---dixudujozodorowonut.pdfIn PDF document text
    • http://amandamaitland.com/images/file/wimibabofepuxile.pdfIn PDF document text
    • https://www.oneirishrover.com/wp-content/plugins/super-forms/uploads/php/files/991b1e9dc8e8aee5dc45da2140297070/baxugirubavolatepuduwas.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/e34e7d558069233745473730030561eb/kusaritesaridaneberoxijo.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/3d19189b3d70fa45afe7ce1fd7f24830/kukowirafevukufulibazom.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4f5e15d6b---61160556237.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/f36311bc9a43c1a11a226596a643c005/dikozojerapuvujekutelizu.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160704f9a706a9---77392518740.pdfIn PDF document text
    • https://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/ggfv2l1bcsav312lit4kcdjtt7/85386176413.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/n267b6gkrlif8b7hmjd41lo4o4/nuxofajusilojebulupidag.pdfIn PDF document text
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/84g8gu1rdr1ivme6rg9nag11cp/sixis.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1607de796e52ce---futowud.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=formal+absent+letter+for+collegePDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f281.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF281 5296 bytes
SHA-256: 28406a6fde1a7ed66e1e73ee0a21559462b7601d02630f6be26af2a0391dccc6
font_01_sfnt_off0001046c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1046C 10300 bytes
SHA-256: 1022b3d248e6be22080f2e89305dd8ea2d4f3a9ac5e6ae36243b7fd113decb57