Malicious PDF — malware analysis report

Static analysis result for SHA-256 4581a07e705c7159…

MALICIOUS

PDF

75.1 KB Created: 2021-09-24 14:50:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 5ad53a276d9936f05eb5e54d9ba70e6d SHA-1: 3aee5b60fe5fa101af77a84cda0416d97b58f47c SHA-256: 4581a07e705c71597c4114e854e1f0873099720b64fd0182310fce27dcaa3bd5
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. Heuristics identified the document as a link farm, with many external URIs pointing to potentially compromised websites or disposable hosting. The presence of multiple URLs, including those on compromised CMS uploads, suggests an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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
  • 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 https://huntic.ru/uplcv?utm_term=avg+protection+apk PDF link annotation
    • http://ombs.ru/uploads/files/kipituzepuv.pdfIn PDF document text
    • http://nhatnamvina.vn/rich_editor/file/zisutus.pdfIn PDF document text
    • http://getem.eu/files/file/44245131661.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/aa24577ff3d815edcb972d6c24ba9198/44943042944.pdfIn PDF document text
    • https://suacuacuontoanphat.com/upload/files/pemewuf.pdfIn PDF document text
    • https://hoya.hr/UserFiles/file/pelefabazutaparunomarujuz.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140bdee8eb04---motudoxaweda.pdfIn PDF document text
    • http://aimecostruzioni.it/userfiles/files/pisonu.pdfIn PDF document text
    • http://sahrugs.com/userfiles/file/27224804977.pdfIn PDF document text
    • http://skisun.it/userfiles/files/nameju.pdfIn PDF document text
    • http://www.biharikft.hu/bihari-admin/ckfinder/userfiles/files/tevazisiludokilevogav.pdfIn PDF document text
    • http://bnblspecialities.com/userfiles/files/84543825042.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/66409911776.pdfIn PDF document text
    • https://keongracun.org/contents/files/wopipopegaluf.pdfIn PDF document text
    • http://abwingssuffolk1.com/uploads/files/34551093075.pdfIn PDF document text
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cb2faee46a---6960016662.pdfIn PDF document text
    • http://sasolution.kr/userfiles/file/gawelabunapajijigeled.pdfIn PDF document text
    • https://www.utn.ac.cr/sites/default/files/files/wufonenutopof.pdfIn PDF document text
    • https://endeligmandag.no/e-brev/data/div/11881958685.pdfIn PDF document text
    • http://gzwep.com/img/file/20219161392.pdfIn PDF document text
    • https://dortmundpools.com/contents/files/41865595380.pdfIn PDF document text
    • https://chaletsuenodesol.de/files/pifixoro.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ae0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE0F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c620.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC620 16244 bytes
SHA-256: fddcbe21bdf9fb2753729b4ab5b26d7a3fbb01e3fe51d41ab0725360e25c189d
font_02_sfnt_off0000dc0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC0A 17100 bytes
SHA-256: 323d039705bf67f258acdc362e14993f69b9da8067f4d53b56bcc60a87ff57ea
font_03_sfnt_off000106f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106F2 10472 bytes
SHA-256: 2b8a5acacaf647517ad6686adb9d05be9458d70b601d13daf83994193313b40d