Malicious PDF — malware analysis report

Static analysis result for SHA-256 1991a1d2fc9a16f7…

MALICIOUS

PDF

82.4 KB Created: 2021-09-05 03:23:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d93cdb32140504c3da0edfae9e19d14a SHA-1: 9294f23cf7fae5b5ac368ecf83cd5258fabe1604 SHA-256: 1991a1d2fc9a16f71886de8a9cb39f19012de0f1602147388164306e21dcf43b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to potentially compromised websites, identified by heuristics as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded links suggest it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://onishi-kyosendo.jp/archive/53756743492.pdf
    • http://calhi1974.com/clients/46234/File/61206282768.pdf
    • https://perfecthospitals.com/ckfinder/userfiles/files/23935128876.pdf
    • http://atthaya.com/file_media/file_image/file/21285239743.pdf
    • https://singaporenotarypublic.com/wp-content/plugins/super-forms/uploads/php/files/c07018506a5005d174345bb7514e8611/juzewajilepurig.pdf
    • http://xn--9w3b270a7kf.kr/ckfinder/userfiles/files/39697913876.pdf
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095aeb46b246---32839752558.pdf
    • https://www.adoz.cz/ckfinder/userfiles/files/31461103509.pdf
    • http://hanabi-la.com/uploads/files/8233703618.pdf
    • http://csc-0898.com/userfiles/file/20210607074436_c8zezx.pdf
    • https://geneticapanama.com/userfiles/file/sixegozikunojodofokilim.pdf
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d889d986da4---tijinobunafifujep.pdf
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160aa08c66f072---dirogowun.pdf
    • http://hoangduy.vn/vn/files/mekavapobofetiw.pdf
    • http://wildpflanzen-planung.de/file/8158539714.pdf
    • http://www.cavice.fi/tiedostot/files/tudiwuxojikaluxaguxusozu.pdf
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a9480135c6---20754986915.pdf
    • http://wisdomtours.net/upload/file/zupenu.pdf
    • http://architects-desk.com/uploadsfile/xufadibimukomuk.pdf
    • https://sy-tech.eu/file/8652772315.pdf
    • https://dovolena-jiznicechy.cz/uploads/14441722917.pdf
    • https://floraplant.gr/FCKeditor/userimages/file/xajodixuxomujajibud.pdf
    • http://globalquestconsulting.com/userfiles/files/panodatudi.pdf
    • https://rlvanstory.com/wp-content/plugins/super-forms/uploads/php/files/07f54632d168ee5e98af20e342a4438c/50930345436.pdf
    • https://girilawfirm.com/content_files/files/70558366172.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=oyster+card+application+form+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d9e8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9E8 16792 bytes
font_01_sfnt_off0000f1ff.bin
0c93d64eb7f0d1b313b21213259c61879d42dee03b607e9774887b449beec417
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1FF 10920 bytes
font_02_sfnt_off00010b49.bin
e5f03a7464ff033961bb684a0cf20a16ea4023bcfcc15a3790d2fed4bb401aca
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B49 18576 bytes