Malicious PDF — malware analysis report

Static analysis result for SHA-256 b50d3518f88c5ad9…

MALICIOUS

PDF

80.0 KB Created: 2021-09-17 15:23:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 8738a311b005dc9b5c4375803a22329a SHA-1: 99c9903184aedead6aed0f701c21dce7863c22c9 SHA-256: b50d3518f88c5ad9a325658e11e6a3f95673db919a7c72cb312e84546f0c4f83
126 Risk Score

Malware Insights

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

The PDF contains numerous external links, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to redirect users to exploit kits. The presence of embedded URLs and the nature of the heuristics point towards an attempt to deliver a secondary payload or phish credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pistant.ru/uplcv?utm_term=dual+app+hider PDF link annotation
    • http://honyi.tw/ckfinder/userfiles/file/xinudedupuvofafexaxinez.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d3268e6071---63876489084.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/1155bf8be5d416b7debeef04cc39bccd/54876986766.pdfIn PDF document text
    • https://fallsplat.se/bildbank/file/xawiluzupetupilesunuked.pdfIn PDF document text
    • http://goldmustang.com/files/files/41306564531.pdfIn PDF document text
    • http://www.niceresidence.net/image/upload/File/85337629231.pdfIn PDF document text
    • https://meesens.be/KrMee/Tekstverwerker/kefepolururupetisebiraluv.pdfIn PDF document text
    • http://studiopignotti.it/userfiles/files/bolasibukunoniputijuxig.pdfIn PDF document text
    • http://nincity.de/inline/file/85848931265.pdfIn PDF document text
    • http://clinivetmadonnadirosa.eu/userfiles/files/taxovopix.pdfIn PDF document text
    • http://aktifimmo.lu/userfiles/files/88982096012.pdfIn PDF document text
    • http://ourgans.org/userfiles/files/radusafifivemagasibega.pdfIn PDF document text
    • http://wirtrauenuns.ch/images/file/4830739466.pdfIn PDF document text
    • http://epoptavky.com/is/images/FCKeditor/File/47600027567.pdfIn PDF document text
    • http://nachhilfeschule.havonix.com/ckfinder/userfiles/files/sepudosakesumegaxex.pdfIn PDF document text
    • http://pilanatofishing.com/home/sandbox/domains/shelter.sandbox.tritek.hk/public_html/ckfinder/userfiles/files/guzegurijilovalu.pdfIn PDF document text
    • http://vngo-cc.vn/cooker/public/files/57064426169.pdfIn PDF document text
    • http://kowalstwwo.pl/public/cms/images/file/kowolofasodikabisanesev.pdfIn PDF document text
    • https://printsolutions.printsolutions.bg/uploads/wysiwyg/files/98253892431.pdfIn PDF document text
    • https://cursosadistanciayonline.com/medios/files/gozoravigalumime.pdfIn PDF document text
    • https://kp-bs.ru/upload/files/tefopabotokukamosijudi.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_off0000d48c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD48C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eca3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECA3 10100 bytes
SHA-256: 94ab41a609f00c42ab020173a05b3fe1c675aa3b87996f1618b4baccdf608a7c
font_02_sfnt_off0001032e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1032E 18204 bytes
SHA-256: e8ecddf59ebced4209b7e7bbc2f319b1d00a82d9151c7aca798056ea6d71dfd8

Open this report in the interactive analyzer, or submit your own file for analysis.