Malicious PDF — malware analysis report

Static analysis result for SHA-256 9277a40e8c7cfcec…

MALICIOUS

PDF

89.8 KB Created: 2021-06-26 09:19:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0db84d2dc4f625a20330398690a3fc6e SHA-1: e780de6632fc0bcb734a67ccd85bbe2a256e0615 SHA-256: 9277a40e8c7cfcecc7aff6979868bd2800eb6076391143931dfd9746b71373cb
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. The sample also exhibits characteristics of a link farm, with numerous external URIs pointing to compromised WordPress sites. These factors, combined with the ML classifier and ClamAV detection, strongly indicate a malicious intent, likely for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://master-sign.ru/ckfinder/userfiles/files/jipupigobizirivisita.pdf
    • https://hssipm.com/wp-content/plugins/super-forms/uploads/php/files/cae5e1b016aeba9a6dbf520291e82d4f/rowekokedulerixekopovine.pdf
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160956ce170203---33190495455.pdf
    • http://vote4dannybarry.com/clients/2/2f/2f5d4f67c16906f9b09010289963de11/File/rizavipunagowevu.pdf
    • http://files.ibiza-ferien.de/file/59328968250.pdf
    • http://serramentisiciliano.it/userfiles/files/85626633919.pdf
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/9e61c9f2a3d6df22ca25cb7e69601c06/jijamulebiredaxowisosi.pdf
    • https://soyana.de/js/ckfinder/userfiles/files/97536338506.pdf
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/9b4f616f4ec405d09477ffb3e39b9e6b/63793130365.pdf
    • https://agatanorek.com/files/file/20333988530.pdf
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086fed72f11d---murumibugoruxit.pdf
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//nimobojatoxigobexirupilor.pdf
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/ptb561u3l24om7i4837gfjk8sh/juzuti.pdf
    • https://telewebmarketing.com/FCKeditor/file/9297299889.pdf
    • https://pirkitpadangas.lt/ckfinder/userfiles/files/towatimabixotenezaromij.pdf
    • https://ancoraeducacion.com/images/48122452972.pdf
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c9209358539---zererilizijarol.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160834ffe34cb9---bozotavupo.pdf
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ba07ed3e23f---37555985307.pdf
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/160c8f23e68d19---kulep.pdf
    • http://dlevitin.ru/fck_editor_files/files/rufet.pdf
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/945003b89070473df0e893c0d6de796f/58103335043.pdf
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/cd2d022f787e1a8736cc157a7aa625df/lobepizemubevodadosa.pdf
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/16097cce2a9bb9---guzej.pdf
    • https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/536fd7555aeeb37514a4fbc84eb5ac07/42282563847.pdf
    • https://lastcallslc.com/wp-content/plugins/super-forms/uploads/php/files/3fc0a4cc214831dc8659e7755cb09d9f/40721523976.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=graduate+teaching+assistantship+in+usa
    • 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_off0000fb31.bin
cd288e8705515c7df7975c4d50ecc7d5e5f2d4a2f3196a9c87563016ff1b704d
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB31 17008 bytes
font_01_sfnt_off0001276b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1276B 16792 bytes
font_02_sfnt_off00013f82.bin
3334f012f5e7aa433f30140fe92bc8a99556a61e73c4e4dee6de03517dfd13d9
pdf-font-stream PDF embedded font (sfnt) at offset 0x13F82 10768 bytes