Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f103c1f229f9eed…

MALICIOUS

PDF

86.5 KB Created: 2021-09-13 12:48:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 91ff39e218b85c6d562582f0d7de666e SHA-1: 16f4bab4270e707ab970bdaf79f6d16a0d3a3f59 SHA-256: 8f103c1f229f9eedd9435cbcb2a9168d9fd5913525aebb9bbbe06a6cd7a98fd6
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and external URIs. The PDF structure suggests it functions as a link farm, directing users to numerous external domains, which is a common tactic for phishing or distributing further malware. The embedded JavaScript likely facilitates the redirection or exploitation process.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://chcial.ru/uplcv?utm_term=offline+fighting+games+android PDF link annotation
    • https://svingenieria.cl/userfiles/file/32017613657.pdfIn PDF document text
    • http://yokohama-model.com/userfiles/files/51001925594.pdfIn PDF document text
    • https://firesystem.ro/imagini_ws/xobogadovox.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/u1egkk4i2t66d3bqbm8tbspj6b/34689812816.pdfIn PDF document text
    • http://blow-w124.com/js/upload/files/kaguzipofijub.pdfIn PDF document text
    • http://guanzhuli.com/userfiles/file/ditifito.pdfIn PDF document text
    • https://dacola.com/upload/files/93693529304.pdfIn PDF document text
    • http://tech-in.info/bramy/userfiles/file/jedusiritovigaxados.pdfIn PDF document text
    • http://sobateracota.ro/mm/file/23929099754.pdfIn PDF document text
    • http://advocaatindex.nl/images/uploads/zakigesuzuveludixozebisiw.pdfIn PDF document text
    • http://signauction.net/userfiles/file/jenimonewagovupi.pdfIn PDF document text
    • https://agriturismoilcolle.org/userfiles/file/jaranivav.pdfIn PDF document text
    • http://crescentcarpets.com/userfiles/file/97719842912.pdfIn PDF document text
    • https://stancijanegrin.com/userfiles/file/nafusefizudu.pdfIn PDF document text
    • http://gd-weimi.com/upfolder/e/files/20210905235138.pdfIn PDF document text
    • https://o-dance.com/upload/files/ravasikapupubezerile.pdfIn PDF document text
    • http://softwaretesting.kr/club/data/userfiles/file/20210907232426.pdfIn PDF document text
    • http://szymonadamczyk.pl/uploads/fck/file/25536066115.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16135d4d773a4c---befikavasomiladajifatisu.pdfIn PDF document text
    • http://velkoobchod-man.eu/ckfinder/userfiles/files/17506095698.pdfIn PDF document text
    • https://adproissy.emailingmanager.com/uploads/editor/file/nebuzemegitexemitowonesu.pdfIn PDF document text
    • https://firesystem.ro/imagini_ws/rogimaxufadomefu.pdfIn PDF document text
    • http://huonglonghotel.com/uploads/image/files/xiviroromalagobediluwujez.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_off0000f05a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF05A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010871.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10871 10824 bytes
SHA-256: 4c0701b9b32787229c5806d251bc0a13d5dac79814bb5db989f88baed5322ac9
font_02_sfnt_off000120fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120FC 16800 bytes
SHA-256: 028f7d896f67e9ec130a83d4673510a3586fd3de214a920a92a7c07cb4e72ff0