Malicious PDF — malware analysis report

Static analysis result for SHA-256 16f74d8d2cba0905…

MALICIOUS

PDF

83.8 KB Created: 2021-08-16 04:18:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dbaba651cb5b4d4cd7d21469ec46dbf4 SHA-1: a3f4b56883de05e949c1d778dd4b7a632d7189c0 SHA-256: 16f74d8d2cba0905c3835abcfd6444a655fa0ae3a36d3d0eedc8166dd7f4cbf5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by multiple heuristics as malicious, including a high-confidence ML classification and ClamAV detection. It contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting it's used for phishing or distributing further malware. The embedded URLs and link farm structure indicate an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c45f8a04aad---lepikonomujozubivolo.pdf In PDF document text
    • http://alexlunacoach.com/img/editor/file/varapajixikubonipegu.pdfIn PDF document text
    • https://fullhousetourism.com/UploadFiles/file/20210622180925148.pdfIn PDF document text
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/59tuj7e0qt72cjvphs8und4t8o/94830144970.pdfIn PDF document text
    • http://maasmartcity.com/userfiles/file/80794088891.pdfIn PDF document text
    • https://puppometalli.eu/file/zebemasufabizo.pdfIn PDF document text
    • http://telmeed.com/web/ckfinder/userfiles/files/misexewo.pdfIn PDF document text
    • http://xn----7sbev0bhje.xn--p1ai/images/news/file/65214777345.pdfIn PDF document text
    • http://www.dereformasenalicante.com/archivos/files/kupokoroxulamasulujep.pdfIn PDF document text
    • http://xn--e1aaafipco3bk8gra3b.xn--p1ai/upload_picture/file/jaxuligekajujevifu.pdfIn PDF document text
    • http://bliksis.ru/userfiles/file/kalirapowemanededifeku.pdfIn PDF document text
    • https://mallncart.com/userfiles/files/68011019679.pdfIn PDF document text
    • http://archidaldegan.eu/userfiles/files/64444207643.pdfIn PDF document text
    • http://physio-praxismitte.de/userfiles/14817284041.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/6b5ccda95d2b902a896b8426fad00d97/41409868557.pdfIn PDF document text
    • http://altinay-law.com/images/file/megugepusamokurudo.pdfIn PDF document text
    • http://dep14kirov.ru/userfiles/file/64311443800.pdfIn PDF document text
    • http://fritz-fahrlaender.ch/download/vurinin.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb0600163d---wiwajofuku.pdfIn PDF document text
    • https://starbox.fr/img/files/4890479597.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/161051c4d1dd0e---zapasitipusazovejanonoda.pdfIn PDF document text
    • https://rlmahtani.com/userfiles/files/rujitizozozanug.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=hunger+games+katniss+quotesPDF 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_off0000e566.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE566 16504 bytes
SHA-256: 1c13babf24945555cedbebf91ad59b0e9dfc35ce0b61d25ab60de5c75569bdc1
font_01_sfnt_off00011038.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11038 10736 bytes
SHA-256: 99b90a98c10a503806bf020109199892801687f18e039374d844a08880060873
font_02_sfnt_off00012890.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12890 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1