Malicious PDF — malware analysis report

Static analysis result for SHA-256 0edefc87017612b8…

MALICIOUS

PDF

81.7 KB Created: 2021-09-15 11:52:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 599fc5f847825953d902486c0faccdcc SHA-1: 9f1db80b2fd639fbc56ae57d0cbd5c58897d63c5 SHA-256: 0edefc87017612b8cf7cd3d53787e3c7c4cf1a180a39b72d5e7b82c604e93303
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The authoring application 'wkhtmltopdf' is not inherently malicious but can be used to generate documents for various purposes, including malicious ones.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://synerhu.ru/uplcv?utm_term=how+can+i+root+my+mobile PDF link annotation
    • https://salvatoredivilio.it/userfiles/file/jugulipipesarabidis.pdfIn PDF document text
    • http://bajcsidavidfoto.com/_user/file/bopawapabusidokuragoxoz.pdfIn PDF document text
    • http://basumati.com/app/webroot/ckfinder/userfiles/files/rikiwobowexofupevawaj.pdfIn PDF document text
    • http://ageddfjtj.pretty-match.com/upload/files/76392735407.pdfIn PDF document text
    • https://www.hosotte.com/ckfinder/userfiles/files/70837773386.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613a274c25447---68025418453.pdfIn PDF document text
    • https://sukhayurveda.in/userfiles/file/75550525138.pdfIn PDF document text
    • http://teraval.cz/res/file/47051607943.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/1613e7bc6b0272---44787326372.pdfIn PDF document text
    • http://sosonomo.com/ckfinder/userfiles/files/37040884388.pdfIn PDF document text
    • https://braveathlete.net/geektic/files/sudapifufotijojuladefat.pdfIn PDF document text
    • https://hchoanglong.vn/userfiles/file/42491984880.pdfIn PDF document text
    • http://dtpokebar.com/uploads/files/21922358382.pdfIn PDF document text
    • http://cu-hinothai.com/ckfinder/userfiles/files/37696912963.pdfIn PDF document text
    • http://bannhuaduong.net/upload/files/87411653062.pdfIn PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/70266673398.pdfIn PDF document text
    • https://kalyna.ua/sites/default/files/userfiles/file/12920584023.pdfIn PDF document text
    • http://aucontecnologia.com/userfiles/files/kuvodov.pdfIn PDF document text
    • http://ohxto.com/uploaded_files/userfiles/files/45073501520.pdfIn PDF document text
    • http://l-max.ru/userfiles/file/givifu.pdfIn PDF document text
    • https://qualitygums.com/userfiles/file/48135600387.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f77c1b5a0b---fidixigoxosisakubazi.pdfIn PDF document text
    • https://inprovitcentroamerica.com/ckfinder/userfiles/files/posurififololobezita.pdfIn PDF document text
    • http://cheniou.handysociality.com/upload/files/sisapetixoj.pdfIn PDF document text
    • http://woykoff.hu/upload/file/85364418050.pdfIn 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://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_off0000da76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA76 18012 bytes
SHA-256: c0f55ad4fd9996024ff5ef60b06c3e0033ea0c62af463f9e1b80004ad3ddfb55
font_01_sfnt_off0001093a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1093A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012151.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12151 10556 bytes
SHA-256: 9903c898d8584d7aa5844fd4bee16d45b28fdeab2408f9e079452e104baf9277