Malicious PDF — malware analysis report

Static analysis result for SHA-256 1203108d236f3b79…

MALICIOUS

PDF

80.4 KB Created: 2021-09-17 19:52:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 81d930495ef4e299eeaa5b6e2fcb7aad SHA-1: b9fd472a9ca84bb97450de9d4d2e881e925eb214 SHA-256: 1203108d236f3b7998c59fcbda29ed1cb9479ce9580468881d26219b830b3df0
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised websites, identified by heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent. The primary function appears to be redirecting users to potentially malicious content hosted on these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://bookblog.kr/data/file/files/4022066930.pdf
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/161361e0ea9131---22967259355.pdf
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/507a1440ae0ea96702592a2b850be646/37065275982.pdf
    • http://izumrud38.com/ckfinder/userfiles/files/70817269442.pdf
    • https://renhedc.com/uploads/files/202109061421312542.pdf
    • http://ingore.cn/upload/files/davipegufegamekonolabulu.pdf
    • http://mdbim.pl/ubezpiecz/obrazy/file/tapelepire.pdf
    • https://postelezmasivu-zlin.cz/ckfinder/userfiles/files/57510532089.pdf
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/1c70543ab4517cd61146320f84218caa/xafok.pdf
    • http://nppgursaraijhansi.in/ckfinder/userfiles/files/20971349611.pdf
    • http://www.pattyn360.com/upload/forum/files/40483171532.pdf
    • http://alkanboya.com/files/file///xadolebagalasarorir.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/16144ba040758d---zobupolenivazof.pdf
    • http://ehomerealestate.org/images/file/nowazilezuw.pdf
    • https://iphone-odklep.si/vsebina/nulagedapemerujiguboxo.pdf
    • http://noithatlekhanh.com/Images_upload/files/93935481347.pdf
    • http://gr-chem.com/upload/files/zegiziduvidijikugavukujol.pdf
    • http://kavtas.com/images_upload/files/30329082867.pdf
    • http://kidzcastleschool.com/singhania/downloads/file/gozesosisizovujanade.pdf
    • http://congseng.com/uploadfile/files/pedikixenorad.pdf
    • http://zerosquareonline.com/file/97292990014.pdf
    • http://auto4-spb.ru/public/images/ckfinder/files/lozanofunisewa.pdf
    • http://forspeed.cz/ckfinder/userfiles/files/21854513260.pdf
    • http://rayer.cn/d/files/godikipawoj.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+remove+sd+card+as+internal+storage
    • 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_off0000d679.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD679 16792 bytes
font_01_sfnt_off0000ee8b.bin
fa39dd942628e2397b15c7b2e766abfb269a0015dc0b90de79d7751bc54cc6e3
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE8B 17036 bytes
font_02_sfnt_off00011a99.bin
24393cbdb487681b12a85f63065da104081173468e5c459be0d9f9d333a79c0d
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A99 10856 bytes