Malicious PDF — malware analysis report

Static analysis result for SHA-256 a521a49b53d7badc…

MALICIOUS

PDF

86.2 KB Created: 2021-09-10 22:17:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e9de1bbf12f0c6b06b90764e9343a09f SHA-1: 9782d727c74878433aa705160d613eb45621bceb SHA-256: a521a49b53d7badc98f717bfe808283593d491e78e515c997b48752af0bdaa2b
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of multiple external URIs and a link farm heuristic indicates an attempt to lead the user to potentially harmful external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://glavis.biz/userfiles/file/80268969666.pdf
    • https://coil.hk/upload/files/manemevolizanire.pdf
    • https://mldom.xyz/web/img/podborky/files/zadesomijogixu.pdf
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/02a1e319937a9f0dc189d44cdc6bf3a4/nutefabaserajofijigawe.pdf
    • http://sz-nuoyi.com/Upload/file/2021090404503065933.pdf
    • http://alfonsoguiggiarchitetto.it/userfiles/files/3889180750.pdf
    • http://brandnewgoods.net/userfiles/file/93669945342.pdf
    • https://samsungdvmklima.com/upload/ckfinder/files/lejuxo.pdf
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/97c6039da0ee15d925aa651da5a31f74/29811286624.pdf
    • https://12shio3.com/contents/files/vazotufiliz.pdf
    • https://fleschimmo.lu/userfiles/files/borez.pdf
    • https://congnghiepxd204.vn/upload/files/65682055975.pdf
    • https://ip-kamera-rendszer.nuttydog.hu/ckfinder/userfiles/files/71290717828.pdf
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613316602d034---vujosulivadedo.pdf
    • http://buyo-g.net/userfiles/file/39730969285.pdf
    • http://agriturismolionsfarm.it/userfiles/files/63213468014.pdf
    • http://inventory-acepipe.com/images/uploads/files/sugapugavafajofa.pdf
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137ac2b1dda5---47426567081.pdf
    • https://commonlawhouse.in/userfiles/file/vegofewapovagige.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f8922dd0e7---33679655444.pdf
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/97bac7f2f507037d2c2b6bb4bb019bb3/27231021455.pdf
    • http://dh-cell.com/ckfinder/userfiles/files/27383251593.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=ringtone+download+mp3+music
    • 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_off0000ebd4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBD4 16792 bytes
font_01_sfnt_off000103e6.bin
930a4bf6a46d35866036f4e7897c5b80a412e6a7179ba01446b6f231211ff8d2
pdf-font-stream PDF embedded font (sfnt) at offset 0x103E6 17624 bytes
font_02_sfnt_off00013191.bin
3431211fd32ef64c879de9db87bc2e143367555b2c7c42ebeef9356915bf57e8
pdf-font-stream PDF embedded font (sfnt) at offset 0x13191 11160 bytes