Malicious PDF — malware analysis report

Static analysis result for SHA-256 33b11e88c2e865fe…

MALICIOUS

PDF

86.0 KB Created: 2021-07-01 19:42:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1107502c0ff0e5479dbef723afd3cbaa SHA-1: d1a67a96864ea2a61a581c46829d83b0aa47fd96 SHA-256: 33b11e88c2e865feb712cbf6c56889badef4893fb8d82d5fe1279fdcedb36362
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document identified as malicious by ML classifiers and ClamAV. It contains a large number of embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The presence of these links indicates an attempt to facilitate phishing or malware distribution, likely initiated via a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://wastran.ru/uplcv?utm_term=constantly+have+to+pee
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/f59589704b3caed078bb44fb7fa4ef36/vegelejupo.pdf
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/160872e2f33ebe---bapukuguzowo.pdf
    • http://humanitool.ru/userfiles/file/kuduravo.pdf
    • http://drive4smilesontario.com/clients/e/ed/ed023a0734c265ca673a92d1d81de675/File/1898843507.pdf
    • http://jfac.kr/ckfinder/userfiles/files/bisaladigipulawubow.pdf
    • http://dush-kz.ru/uploads/fck/file/51248850171.pdf
    • http://amirafouad.com/uploaded_files/file/27701345312.pdf
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160887904a3f2a---viwurapor.pdf
    • https://dmvassociates.com/wp-content/plugins/super-forms/uploads/php/files/5ee63a2cb8ffbeb443e6f0254aa081a0/39182989941.pdf
    • http://autavrabek.cz/obrazky/file/68303468537.pdf
    • http://sklepjola.pl/userfiles/file/98753829012.pdf
    • http://ideas4mypool.com/userfiles/file/37609937286.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607161a9ecc8f---28378641030.pdf
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074303c906e6---57235291155.pdf
    • http://spearsyounglegacy.com/clients/b/b2/b2c23f164518415ec8f3c1c8d0af542d/File/powapodobunitubure.pdf
    • https://aymfly.com/aym_image/files/39243530717.pdf
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160893a204fefd---25029807069.pdf
    • http://botosani.ro/img/uploads/file/wonadexevoli.pdf
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/83ecd3567f9101823962ec906e2cefce/21181507861.pdf
    • http://getampedmag.com/ckfinder/userfiles/files/mezilofidakijutir.pdf
    • https://rkdestate.com/userfiles/file/badupulerodox.pdf
    • https://www.m2asolutions.com/wp-content/plugins/super-forms/uploads/php/files/d3ebbe05f97e987980810fcce47b8fa0/lisoperakarufox.pdf
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c5e4c8c13a8---gatidudusowupapulubekafa.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_off0000f0df.bin
7ff40f948465076fdce43f4c08e6e864703657933970579f3a185e3ad72fb04e
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0DF 10368 bytes
font_01_sfnt_off00010860.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10860 16792 bytes
font_02_sfnt_off00012072.bin
93198b42532c5427da87b0156b2f494b4dab90b5c6ef07f24d107557989f9c39
pdf-font-stream PDF embedded font (sfnt) at offset 0x12072 16408 bytes