Malicious PDF — malware analysis report

Static analysis result for SHA-256 743677e502b2a5c3…

MALICIOUS

PDF

94.2 KB Created: 2021-08-09 13:42:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a3f2bb19eddb8c2f73453f23ff1ff6cb SHA-1: 149765a904b6e9d3853970fadbc0449347d48c01 SHA-256: 743677e502b2a5c3ad41d70e58b74c0ff9ef54fac0317a14ed324707a65e5505
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing an embedded JavaScript stream and a large number of external URIs, many of which are part of a link farm hosted on compromised or disposable domains. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery through these links. The embedded JavaScript may be used to further obfuscate the malicious activity or initiate a download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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 https://infrive.ru/uplcv?utm_term=ejercicios+numeros+cuanticos+resueltos
    • https://dm288.com/slicice/file/juruzezowutogasir.pdf
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16106b57871e15---79075254929.pdf
    • http://sl1971.com/clients/5/51/517263f0417f9379c67e6eba0e0bdfe8/File/55326279560.pdf
    • http://chhsmahs.com/clients/8/83/83f479e57a8bbaec88b4a04d821ef24e/File/41299182659.pdf
    • https://menu2uplus.com/images/file/53658821130.pdf
    • http://studiolegalezullo.eu/userfiles/files/vejalenolegamabaravevusa.pdf
    • https://heyratacademy.ir/file/19614816089.pdf
    • http://doks-films.com/pcms/content/file/18077559981.pdf
    • https://electrodomesticaruano.com/images/ckfinder/files/fevifofuzaj.pdf
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/a9b631aa8464544d23c228cb3a77ee7a/6827440851.pdf
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b13448f416---xulujafoju.pdf
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608782bc93299---dilizadepokejuvosegowuxa.pdf
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/an8rgmqf8ecie7lbvr82caa8mv/35230662151.pdf
    • http://sushistoryus.com/uploads/files/16883421388.pdf
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce37fc08a51---45742450402.pdf
    • http://raiporjai.com/piceditor/file/29923124994.pdf
    • https://fentesmakina.com/paket/upload/files/95886086767.pdf
    • https://taksis.lv/taksis/userfiles/file/93295042189.pdf
    • http://alliusie.com/userfiles/file/37143372231.pdf
    • http://1137.jp/app/webroot/js/ckfinder/userfiles/files/bepexut.pdf
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160929d52d48c9---jiwulavewuloditug.pdf
    • https://francois-daulte.com/ckfinder/userfiles/files/17699023115.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_off0001082d.bin
d19d6351eeb4e07f96088bd01815b2552b3c8242110a1e979bbec7b5259a56f0
pdf-font-stream PDF embedded font (sfnt) at offset 0x1082D 19264 bytes
font_01_sfnt_off000138e8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x138E8 16792 bytes
font_02_sfnt_off000150ff.bin
85cac73b5edd5898292cb58669e268a48cb6212377eba527dd6a8fa130ceee7a
pdf-font-stream PDF embedded font (sfnt) at offset 0x150FF 10604 bytes