Malicious PDF — malware analysis report

Static analysis result for SHA-256 af4056290442904f…

MALICIOUS

PDF

86.1 KB Created: 2021-09-04 12:56:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 4cc4c146eba31f187a099eed27d3de53 SHA-1: 82bb33a90f758a7b25076fba13faed41d2687347 SHA-256: af4056290442904f276f9bb430b346127f0677ea3dc1397a9fe4d78ec9a6ec55
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised WordPress sites and potentially disposable hosting. The document body is heavily obfuscated, preventing analysis of its direct content, but the overall structure and URL analysis strongly suggest a malicious intent to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/f0sk3m24uf2tdrrovh0bln0mc4/joxoja.pdf In PDF document text
    • http://bjsixiang.com/jingkelun/userfiles/files/20210904071520.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16132c711d5567---xixelinimaratulozili.pdfIn PDF document text
    • http://st-communications.com/ckfinder/userfiles/files/93568194433.pdfIn PDF document text
    • http://wf515345.tw/CKEdit/upload/files/35848727838.pdfIn PDF document text
    • http://ueros.fr/admin/ckfinder/userfiles/files/97353281032.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/56813706885.pdfIn PDF document text
    • https://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/fqiidf9h88du27fh0ejb6r2v00/62778757991.pdfIn PDF document text
    • http://www.anieliasfx.com/uploads/textareas/file/lutekudozabumakolu.pdfIn PDF document text
    • https://fajndoktor.cz/images/file/files/nogamoniradutinepun.pdfIn PDF document text
    • http://tort-art.ru/userfiles/file/80292682790.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/gf5l4rqj6pvvfi55sl3iaplt37/51152699281.pdfIn PDF document text
    • https://gamma-electronics-eg.com/userfiles/files/21778752459.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160ded634e6436---51550545293.pdfIn PDF document text
    • https://rajatotogroup1.com/contents//files/93736569354.pdfIn PDF document text
    • http://carrasvilla.es/uploads/files/buzefuvetisemijogo.pdfIn PDF document text
    • https://mallncart.com/userfiles/files/60828524763.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2413827d30---83739634296.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c95ef1d1b3b---ranex.pdfIn PDF document text
    • http://1mosref.ru/ckfinder/userfiles/files/13187114252.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=rekordbox+manual+portuguesPDF 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_off0000e124.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE124 11120 bytes
SHA-256: 8ce2c358d01db2ac7a9feed5a7ca6e5647db0f471615808d4904b9160f9bddab
font_01_sfnt_off0000fab6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAB6 21756 bytes
SHA-256: f832a6f48e38e0b7a7adf8de70334fc44559f194bb9a72ba03d82d1db7e8af4b
font_02_sfnt_off000133a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133A9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1