Malicious PDF — malware analysis report

Static analysis result for SHA-256 77d7cd05d5c99e45…

MALICIOUS

PDF

81.8 KB Created: 2021-09-19 14:48:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 39ad3e28526c77877c6077ff4839ae88 SHA-1: 878c7e4077eee9c7154c6eee6e315fdee7caf900 SHA-256: 77d7cd05d5c99e45d0af9d1d9ef79f5492cb6a912546189449f3654d66decea1
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and a machine learning classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous external URIs, many of which point to disposable domains and are structured as link farms. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically flags this behavior, suggesting the document's primary purpose is to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://queure.ru/uplcv?utm_term=bad+time+simulator+mod
    • http://foxgraphics.paulsfashion.in/files/72300136799.pdf
    • http://lexus-custom.com/js/upload/files/fozubuzifag.pdf
    • http://citty.org/images/uploads/file/32582699861.pdf
    • https://robustbrakes.com/administrator/imagetemp/file/fijonawiwup.pdf
    • http://nwatchonline.org/userfiles/file/45339714779.pdf
    • http://mijn-nederland.nl/userfiles/file/3304604394.pdf
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/161425fd78cbd4---13842384284.pdf
    • http://ctnphrae.com/ckfinder/userfiles/files/kafuvezigoba.pdf
    • http://wdnederland.nl/file/57829372033.pdf
    • http://kamnitikamini.si/upload/files/xotalo.pdf
    • http://asckhn.com/acskhn/userfiles/file/runifisuf.pdf
    • http://sjatupornservices.com/file_media/file_image/file/2549219058.pdf
    • https://enilubricantvn.hoakhanh.vn/uploads/image/files/50688682066.pdf
    • https://www.milestonesmn.org/ckfinder/userfiles/files/69685135074.pdf
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161326adf372ee---vadinemujufiwonajuvizitud.pdf
    • https://drosamahetta.com/userfiles/file/2778711640.pdf
    • https://mjrspot.com/fckimages/file/6325556887.pdf
    • https://eyetracking.pl/userfiles/file/9919033391.pdf
    • https://luckysurface.itweald.com/uploads/files/613283455b6a9.pdf
    • https://olterus.net/contents/files/42701570333.pdf
    • http://smirna.pl/files/file/69464205382.pdf
    • http://www.prakashirrigation.com/uploads/fck/files/40196008618.pdf
    • https://samirkumarpaul.com/ckfinder/userfiles/files/24953038966.pdf
    • http://graylegalservices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fujivesudemovibewuv.pdf
    • 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_off0000d7b8.bin
37fc432bbde0f6edafe1f92d78bcd9508b3be351665d9078ab9bcbe2621dcdd5
pdf-font-stream PDF embedded font (sfnt) at offset 0xD7B8 18900 bytes
font_01_sfnt_off00010996.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10996 16792 bytes
font_02_sfnt_off000121ad.bin
f6dc0d1a75b0466e43606b35229214867cc1dc492746402da70d355824fa533b
pdf-font-stream PDF embedded font (sfnt) at offset 0x121AD 10460 bytes