Malicious PDF — malware analysis report

Static analysis result for SHA-256 5d53bbd797753740…

MALICIOUS

PDF

79.4 KB Created: 2021-07-09 07:46:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: c79e8174b175f8bd51d5d652e279f521 SHA-1: 6d947c658314521d7aaedd48d03299f50152c806 SHA-256: 5d53bbd79775374070b8e1134d1c61c004287108ab8aeeb22c538b0ad6664087
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was detected as a malicious PDF by ClamAV and an ML classifier. It contains a link farm pointing to multiple compromised WordPress upload directories and disposable hosting sites, suggesting an attempt to obscure the ultimate destination. The presence of numerous unknown URLs indicates a broad distribution effort, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 6

  • 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.
  • 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://studioego.cz/userfiles/file/xaviwajozujixepin.pdf In PDF document text
    • http://www.kilincsweb.hu/fileok/file/68347312881.pdfIn PDF document text
    • https://giovannicaputoboutique.com/file/44495318647.pdfIn PDF document text
    • http://club-integra.ru/userfiles/file/17091644957.pdfIn PDF document text
    • https://rockyshairsalon.com/wp-content/plugins/super-forms/uploads/php/files/msrl4ufn4pbha351jpk0th4vpp/baxuxerovimenufojadof.pdfIn PDF document text
    • https://doganagolosa.it/file/rasug.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e631648cb2---furalebekijibajetos.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607e7a514cbce---felireko.pdfIn PDF document text
    • http://okuninka-biale.pl/userfiles/file/gekesegodanikuwolene.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077ce260801b---81247417084.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/09c248b5cfc03311acb821fb031414b9/jodor.pdfIn PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/0059f72b58f247239b9c055a6873eaec/16317376167.pdfIn PDF document text
    • http://norilskgu.ru/userfiles/file/73365474221.pdfIn PDF document text
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e7867d6a32---67812926258.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///1367904719.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609aac3f03eef---sogagisidiv.pdfIn PDF document text
    • https://www.psalighting.com/wp-content/plugins/super-forms/uploads/php/files/e7429b3ca97bc1f2e1ce73f7dc433fc3/lemojufapofikej.pdfIn PDF document text
    • http://tamker.hu/userfiles/file/36376413012.pdfIn PDF document text
    • http://kowel.com/ckfinder/userfiles/files/1625065685.pdfIn PDF document text
    • https://wfca-czech.cz/temp/userfiles/files/rewered.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609890a6a72f9---donedovaxomel.pdfIn PDF document text
    • http://dcbestwings.com/uploads/files/77957743864.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa3ea7ab5e---fekutux.pdfIn PDF document text
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/q3mqspgfqr8sarop0j7jmpgvul/zifafonid.pdfIn PDF document text
    • https://himalayanwanderer.com/himalayan/userfiles/files/92499061642.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/cik7u26lk63j3sdjrb4k36oo5g/gozutidiwu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=javascript+sort+table+by+columnPDF 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_off0000cff6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFF6 17776 bytes
SHA-256: 2e3c0c5d2a338b2dc05f5fb4aa4c5029024a81ec0612e0ddec3cc78640027d20
font_01_sfnt_off0000ff02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF02 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011719.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11719 10944 bytes
SHA-256: 56593e594ecaaeca763de057c95dc634c523e6f8483e90d72a2835f06e22e9b8