Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1bbce9f1425dc37…

MALICIOUS

PDF

86.9 KB Created: 2021-06-26 03:00:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 73bbc37cd69821be268844c7842f6239 SHA-1: 1a7704418dc83c6c15111e124540cee3f4a0b735 SHA-256: f1bbce9f1425dc37784394f57b96b297f95c9818e61f3800e9c4c22a787f631c
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites, a common tactic for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious content or download further payloads. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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 https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072051b6da2b---kafofojipaxobotomovaso.pdf
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/656a5615b7fc281ca457ac39ea137f31/89550527674.pdf
    • https://www.ergunaygoren.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c84a161e32---8511736674.pdf
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/3cjs980pjfqole26hdjqdcer68/botomikuw.pdf
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/7g3st2afpsbl03j5l5i19vv5n6/wamozu.pdf
    • https://al-farh-iq.com/upload/userfiles/file/merovaxufisevowu.pdf
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/18i3i8u816hosq1iscasghaeq1/zevivowusojutudelirupinez.pdf
    • http://restravel.ru/ckfinder/userfiles/files/85017789175.pdf
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/o77dlp49llrb0v3su6s3075rh3/26734330162.pdf
    • https://implant-drill.com/userfiles/file/kedewodedufegi.pdf
    • http://allg-gyn.ch/userfiles/file/12383483167.pdf
    • http://www.aportecnica.com/imagenes/editor/file/86692633697.pdf
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/ad3444ef45289a9ada919c25f1b6828b/makowuwovijajolos.pdf
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/81230e0e48cd734b861fc62edfab1d6d/7507184818.pdf
    • http://citadelcaralarms.com/userfiles/file/rojewijerof.pdf
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/76d53431c948d5a5de080e24775a27da/lafet.pdf
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/03pg8o864v1jm4bljpfgc1eg01/pizapowojagofevetafokagu.pdf
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160882f9cd8212---83986677705.pdf
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160cb8bf5f1f8c---kakotenej.pdf
    • http://kaupa.cz/userfiles/file/jamenapozadewovevuz.pdf
    • http://hvpeds.com/upload/contents/file/66853143419.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+change+the+page+size+of+a+pdf+file
    • 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_off0000ef8c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF8C 16792 bytes
font_01_sfnt_off0001079e.bin
42ec67ec2de98bdb402288d71d7996dc8fa72dd8a8867d6c2d129ff73aa854f9
pdf-font-stream PDF embedded font (sfnt) at offset 0x1079E 17240 bytes
font_02_sfnt_off000134df.bin
2028d36fb1c88eb991aa7e711d95aed0f90a133a821aa86be1e4bf2f4f8ead58
pdf-font-stream PDF embedded font (sfnt) at offset 0x134DF 10936 bytes