Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3e56d6d66913bc1…

MALICIOUS

PDF

68.5 KB Created: 2021-09-30 21:34:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 8260e06a4c48a3f21c3862b9b563edfb SHA-1: d280a9fde6d01ea908d4b5be095366554a8c8fc4 SHA-256: a3e56d6d66913bc1d01b5c13a81853ebab50ce2a8cacb237e6c4a1fa741a5b89
156 Risk Score

Malware Insights

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

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains a link farm pointing to multiple external PDF files hosted on various domains, suggesting a phishing or malware distribution scheme. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, as these indicate attempts to obscure malicious links or leverage compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://chasehr.in/userfiles/file/51300919680.pdf In PDF document text
    • https://playworkspartnership.ca/sites/default/files/file/padudilaloxe.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/161326f7d3adb2---makag.pdfIn PDF document text
    • https://siangyun.com/upfiles/editor/files/23956755430.pdfIn PDF document text
    • http://nutronicltd.com/userfiles/file/30136251609.pdfIn PDF document text
    • http://geasit.it/userfiles/files/resadefuwonawu.pdfIn PDF document text
    • http://bbfrontedelmare.com/userfiles/files/75273450265.pdfIn PDF document text
    • https://pastijptoto.com/contents/files/zikemepukuw.pdfIn PDF document text
    • https://ghnservizi.com/file/vudiwafifugenane.pdfIn PDF document text
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/e8635a021b97c0f1a86a27494ca1fb7f/53194831174.pdfIn PDF document text
    • https://moulindelarroque.com/userfiles/file/vulovabutiditopupapojotu.pdfIn PDF document text
    • http://portalcom-b2b.es/img/user//file/_0797012001631781996.pdfIn PDF document text
    • http://montazerangroup.com/uploader/file/wutap.pdfIn PDF document text
    • https://karolinanowak.com/userfiles/file/46566576721.pdfIn PDF document text
    • https://megacook.pt/site/upload/file/powomusosujatenojelegufaz.pdfIn PDF document text
    • http://robertfeinberglaw.com/images/edit_images/file/30475273052.pdfIn PDF document text
    • http://jsdarvin.com/files/64369241007.pdfIn PDF document text
    • http://gearcon-eng.com/file_media/file_image/file/89637931480.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/af62fd8b9d7cf3eec493eded313673a2/fubisorafoseve.pdfIn PDF document text
    • http://krcatikyonetimi.com/userfiles/file/43410396702.pdfIn PDF document text
    • https://siahotel.com/userfiles/files/pevezapipije.pdfIn PDF document text
    • http://mikol-styl.cz/userfiles/file/45989283311.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=gta+san+andreas+and+obbPDF 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_off0000af9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF9E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c7b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7B5 10284 bytes
SHA-256: af99a23048c536cbbc5a97ca0ee9a9fba87184616645d4577bd585065628bde9
font_02_sfnt_off0000df00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF00 14972 bytes
SHA-256: 52376ad08688ee2859313a79f8a3f9a4c070683509be51479cdf40af073c5efe