Malicious PDF — malware analysis report

Static analysis result for SHA-256 834bde42fa1d13e3…

MALICIOUS

PDF

87.9 KB Created: 2021-07-17 06:44:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: eec6b692d6fb5c9b1a7d1dd3f1dee48d SHA-1: a04d0324cd49952c80710ecb30ff5baaab79c7e5 SHA-256: 834bde42fa1d13e3657a3b8bdba3d047fad21838fc7fe7e48ac31827c53d61ba
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is a common technique for executing malicious code. The document also features a link farm with numerous external URLs, many hosted on compromised CMS platforms, suggesting an attempt to redirect users to malicious sites or download further payloads. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://serextion2006.com/js/upload/files/xesesariduzukupu.pdf In PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609cb490cb9c9---mimem.pdfIn PDF document text
    • https://ckmusicdesign.nluserfiles/file/tebajunudigekigam.pdfIn PDF document text
    • https://asiaviews.org/wp-content/plugins/super-forms/uploads/php/files/4gsvo5qrglmdbj673dmb08gbr3/suvivilojutomigekikowiw.pdfIn PDF document text
    • http://metafelix.it/userfiles/files/5327048969.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1607974536a2a5---4242873613.pdfIn PDF document text
    • http://radio-salsa.com/php/rs/filesupload/file/xolunifogojavunepaziniro.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/e03c963f0a6ea72c117f6ba846575b33/66765061326.pdfIn PDF document text
    • http://mamnonlittlesun.com/upload/files/33862473032.pdfIn PDF document text
    • https://nakipoglugroup.com/upload/ckfinder/files/89800585035.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b8b2908517---78805655812.pdfIn PDF document text
    • http://adbuffalony.com/uploads/files/sagurebarufutobavo.pdfIn PDF document text
    • http://zdravi-kromeriz.cz/files/file/purososik.pdfIn PDF document text
    • http://mygotour.com/FileData/ckfinder/files/20210703_830DE28D9A0EE657.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ogkntat8n556cv5cjir44jiie3/98002563850.pdfIn PDF document text
    • https://trickapotisk.cz/webpagebuilder/ckfinder/userfiles/files/tixaxudigotitasoza.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/d8db9ad4835fb17dc6440c8c7ded938a/xexarazifikakaderufite.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=example+of+an+omnivore+isPDF 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_off0000f679.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF679 10572 bytes
SHA-256: ae2b763f03abe173816e74bd33252abd48918d0f7ca79331f3e3c9831cf83a63
font_01_sfnt_off00010e90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E90 16976 bytes
SHA-256: ec8eb7899300623c4a2820529b7d8d7764a3e1cd80edd7f2bfa6644c71ae27be
font_02_sfnt_off00013ad5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AD5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1