Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a91afcf2a31b5d3…

MALICIOUS

PDF

86.9 KB Created: 2021-09-11 08:46:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: da62fe43ee1eeaee4d65fb4b5c3ce037 SHA-1: 51e057139c3cf5d54daac90c210ac463814b2bb0 SHA-256: 4a91afcf2a31b5d33136ff9bc88d06f2880f98f3ce0f806eafbddddb34b71083
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised WordPress upload storage locations and other disposable hosting sites. The embedded URLs suggest an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://szmchem.com/userfiles/file/49452955415.pdf In PDF document text
    • http://wsmr.us/userfiles/file/83778267464.pdfIn PDF document text
    • http://qcfloor.com/userfiles/file/zaroz.pdfIn PDF document text
    • http://khocabien.com/uploads/files/nejig.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/vuvetefapetowezexesamore.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613788887b05d---59275397272.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613888552a257---numizanobu.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613be859f3ffa---towujobirenexasatebuji.pdfIn PDF document text
    • http://assushop.com/userfiles/assushop.com/file/legelejubenawetalaj.pdfIn PDF document text
    • https://winpoasia.com/ckfinder/userfiles/files/tewifogedewuvegutevoxewar.pdfIn PDF document text
    • https://eastmangroup.org/ckfinder/userfiles/files/45757721464.pdfIn PDF document text
    • http://guides2alpes.org/uploads/file/dejozab.pdfIn PDF document text
    • https://debcopharma.com/userfiles/file/bipedufun.pdfIn PDF document text
    • http://nhuaduongnhapkhauaz.info/upload/files/vopanimokovokepukoli.pdfIn PDF document text
    • https://pilot-nav.com/ckfinder/userfiles/files/24415748488.pdfIn PDF document text
    • http://e-photo.lv/ckfinder/userfiles/files/boluwulowotiwa.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/50a4ef848b86b6027f810afc29bfd612/selilijifiwitajulolem.pdfIn PDF document text
    • https://moveo-sport.pl/userfiles/file/tiwawe.pdfIn PDF document text
    • http://cerezolorente.com/files/cerezolorente/_repo/file/73282266232.pdfIn PDF document text
    • https://luckysurface.itweald.com/uploads/files/612ee18ccdfed.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/94171792ddc63e6877a875eb0de751b2/28751178838.pdfIn PDF document text
    • http://4chan.ro/UserFiles/file/83268591331.pdfIn PDF document text
    • https://legacydockandmarine.com/wp-content/plugins/super-forms/uploads/php/files/aa5533baba0b4c4505cd425eeaa914da/70870731785.pdfIn PDF document text
    • http://decom.pro/admin/ckfinder/userfiles/files/pufopajuraruz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=dodol+launcher+themesPDF 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_off0000e584.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE584 21204 bytes
SHA-256: f618cebeaf545c863f77eb1a224bbb1c44aaaf4782fec0a3d1859500472b300a
font_01_sfnt_off00011dc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DC3 10644 bytes
SHA-256: 4f530f02c737ef72e06514c10d45dbcac99bc39af716684ad36ee14e3e4a16dc
font_02_sfnt_off000135f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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