Malicious PDF — malware analysis report

Static analysis result for SHA-256 85ef1520e54382ae…

MALICIOUS

PDF

78.6 KB Created: 2021-09-22 22:52:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4b0f75520843c92f0095423d9046b5b0 SHA-1: 6646651bf4e357b49e352e02072ec96ce817427e SHA-256: 85ef1520e54382ae2d292f94d6c87c054ec8b898611b4228f17ab10e34702d7d
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan delivery mechanism. It contains numerous embedded URLs that point to compromised websites and disposable hosting, functioning as a link farm. The primary heuristic indicates external URI redirection, suggesting the document's purpose is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://infrive.ru/uplcv?utm_term=audio+video+download+vidmate+app PDF link annotation
    • http://electriccityusa.com/images/fck_uploads/file/xozusateporore.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b877826c8f---9851470338.pdfIn PDF document text
    • http://yao-cheng.com/uploadfiles/20210919003517.pdfIn PDF document text
    • https://sistemagestiondpr.co/userfiles/file/3853957332.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16137a93fed92d---85829944418.pdfIn PDF document text
    • https://angkalaris.com/contents/files/69384953203.pdfIn PDF document text
    • http://makinsushi.com/uploads/files/57607732508.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/161370eb49cdec---77026341689.pdfIn PDF document text
    • http://www.ambatownship.com/ckfinder/userfiles/files/bujekuvawakolixe.pdfIn PDF document text
    • http://dxczx.com/ckfinder/userfiles/files/20210902_234818.pdfIn PDF document text
    • http://closehorses.com/userfiles/file/jidasorowibesazeg.pdfIn PDF document text
    • https://www.tratedu.net/ssss2018/assets/143ad273/ckfinder/core/connector/php/upload/userfiles/files/aa4f8e9afdf3f65f744f2ada41192045.pdfIn PDF document text
    • http://amandamaitland.com/images/file/lofufa.pdfIn PDF document text
    • http://hanleyresources.com/images/paporuwatukifu.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/67100056537.pdfIn PDF document text
    • https://cli-kh.com/uploads/files/202109120401019947.pdfIn PDF document text
    • http://mtegl.wsystem.sk/userfiles/files/30289469220.pdfIn PDF document text
    • http://dent-pro.cz/pic/file/61365972516.pdfIn PDF document text
    • http://studiomarazzi.eu/userfiles/files/82286821002.pdfIn PDF document text
    • https://garnet-medical.com/userfiles/files/sugesinigibatofaxituti.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e0dc6be188---16507439511.pdfIn PDF document text
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/fae0e7a9f787f9361b3c0466f8d0c12b/8792569133.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_off0000d1f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ea0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA0C 10520 bytes
SHA-256: 565f7c62d6e9a340b2d1ecab4355d1b2a9d8ce5519f6ec4352177ef4ddcbebca
font_02_sfnt_off000101fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101FD 16848 bytes
SHA-256: 248002d37e0d74b2bead7f20b7df098809f276f466f6259d8d8c8584a8f0b9df