Malicious PDF — malware analysis report

Static analysis result for SHA-256 37ec763c1753eee8…

MALICIOUS

PDF

86.7 KB Created: 2021-06-25 14:09:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ca80b47e1b5402ee4517951986436c25 SHA-1: ccd7a1b3969e0c801115fdcca783cce138406532 SHA-256: 37ec763c1753eee865b3fcfb39b514ac6910910e7c89f59964ca3aebfebbd31f
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file functions as a link farm, containing numerous links to external URLs hosted on compromised WordPress sites. These links likely lead to the download of further malicious content, as indicated by the ClamAV detection and ML classifier. The presence of embedded URLs and the nature of the heuristic firings suggest an attempt to lure users to malicious sites, potentially for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://catamma.ru/uplcv?utm_term=tale+as+old+as+time+piano+sheet
    • http://sosnovgeo.ru/userfiles/file/xedotidigonutoja.pdf
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079b4d7d1786---95655308824.pdf
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/bed9f94c1172782e3b5a02cf0a769690/bapafe.pdf
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/927371ec1559c2ebead46828c72b991e/nixebanifebufeniri.pdf
    • https://cgeminfos.ma/upload/file/gezowizozanijevusox.pdf
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160acc8cacf0ea---xarorul.pdf
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/r80ujad1rjor6bku767fmunbdv/xoparu.pdf
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075c46e1be76---rotewekazojaz.pdf
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/7806f0e79465c995c10d26e64dc5a086/xudufizer.pdf
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/160710dae1a695---68212299242.pdf
    • http://msci.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1607a575cb91e4---81424833016.pdf
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160872956582d4---59989854280.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/42sa6qrjpjejh56cqt0ioohhuk/80172928560.pdf
    • https://recapress.com/ckfinder/userfiles/files/59015824534.pdf
    • https://contabil-fiscal.ro/mm/file/sabirujebo.pdf
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/ec2b554f1d7b0028f86fb76a25111924/tewawesokefutekir.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e42e.bin
b5d3be551dbf29eaf85cfc6f7c3ba9bc8d7ad7b839a997835e98853d0709c405
pdf-font-stream PDF embedded font (sfnt) at offset 0xE42E 17756 bytes
font_01_sfnt_off000112e3.bin
e3fb196e875c84e6ea40ec077e67d69574999d6807e23fdf28e29781743c6623
pdf-font-stream PDF embedded font (sfnt) at offset 0x112E3 2556 bytes
font_02_sfnt_off00011db5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11DB5 16792 bytes
font_03_sfnt_off000135cc.bin
966416db63dd62b1da65ac8724e66a8c75f7905f42ae69bacacd80ebd89fb878
pdf-font-stream PDF embedded font (sfnt) at offset 0x135CC 10520 bytes