Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca9851cc0f3b9c1a…

MALICIOUS

PDF

84.8 KB Created: 2021-09-13 23:50:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0523e88cfc2f87e4347d43213d5bf79d SHA-1: 0d3855956fcc21f1341e531990f2a151cd8c1ec6 SHA-256: ca9851cc0f3b9c1a3313a6ebe7f27a4c7afef3c37639c180064bb91123556442
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. This script likely redirects the user to a link farm, as indicated by the numerous unknown reputation URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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
  • 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://esistore.be/userfiles/file/71149849472.pdf In PDF document text
    • http://saigondome.com/uploads/userfiles/file/10400667632.pdfIn PDF document text
    • https://5uempat.com/contents/files/tujilenekojifazirozoxutap.pdfIn PDF document text
    • http://bbfederico2.net/userfiles/file/jifiwirisit.pdfIn PDF document text
    • https://cungcapthitdetuoi.com/app/webroot/files/images/pages/files/dobitawizurizezomisijiv.pdfIn PDF document text
    • http://gradn.ru/uploades/fckeditorfile/reporeguwamasavotew.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161330f244903a---kukejixitavadunegi.pdfIn PDF document text
    • http://hiace-yoshikawa.com/js/upload/files/luduxoduf.pdfIn PDF document text
    • http://airfa.it/userfiles/file/80201771199.pdfIn PDF document text
    • http://sydjpg.com/images/upload/file/20210905_073702_180.pdfIn PDF document text
    • http://freewest.at/zelomozovejit.pdfIn PDF document text
    • http://24hnbc.com/assets/ckfinder/core/connector/php/uploads/files/27258079084.pdfIn PDF document text
    • https://www.cascatai.com.br/ckfinder/userfiles/files/95391257561.pdfIn PDF document text
    • https://rimi.sk/userfiles/file/84173579150.pdfIn PDF document text
    • http://terralis.net/catalogue_dynamique/file/kuvenimewiruxivojibugiw.pdfIn PDF document text
    • http://oishisushigd.com/uploads/files/xivusif.pdfIn PDF document text
    • http://agrostroi-proekt.ru/ckfinder/userfiles/files/dodexefezava.pdfIn PDF document text
    • http://olgapolyakova.de/files/files/91308053494.pdfIn PDF document text
    • http://cee1968.com/ckfinder/userfiles/files/91545363403.pdfIn PDF document text
    • http://glassick.com/userfiles/file/bijemaz.pdfIn PDF document text
    • http://sinching.com/uploadpic/files/202109071129024661.pdfIn PDF document text
    • http://barefoot.pl/userfiles/file/16739650113.pdfIn PDF document text
    • http://architettipassarinmarzotto.com/userfiles/files/binosevex.pdfIn PDF document text
    • http://xn--80aafbjcazdrhzgiddbbcsg4l.xn--p1ai/pict/file/lekezuvorepubup.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4d61cc9f08c14e94683d16c3049f7aa8/jemumapokamemupapifujotim.pdfIn PDF document text
    • http://dealershop.es/userfiles/file/zovudopuwifofuwuneviw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=how+to+convert+pdf+into+jpg+on+macPDF 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_off0000e45c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE45C 11020 bytes
SHA-256: 4c1155320bf1803e58a395aa7d4f0edcec0604ff4b9f83ca1e961eb70d64f6d8
font_01_sfnt_off0000fdc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDC0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000115d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115D2 18508 bytes
SHA-256: 229ea7638dd56bc65dd2656a87ef0fefa98b15676f95b03629e989e3cf7dd4b7