Malicious PDF — malware analysis report

Static analysis result for SHA-256 1866cb522f1a9203…

MALICIOUS

PDF

85.4 KB Created: 2021-06-27 12:48:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: b28916e6764f2a9d93b9a8ba95eacfa1 SHA-1: e4ff1f19afce8cd9ad67d203056e9938395cfd12 SHA-256: 1866cb522f1a9203197143f18d86549d00deed06bb885c6b44d64c5f5947d214
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://botosani.ro/img/uploads/file/93815127137.pdf In PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609f6e2e093fb---najowif.pdfIn PDF document text
    • https://europeancustomtailor.com/wp-content/plugins/super-forms/uploads/php/files/829bc2e96692b35537b10f9d8375fb2e/22553921759.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160810a43e2b85---zopadufavinonike.pdfIn PDF document text
    • https://www.sacda.org/wp-content/plugins/super-forms/uploads/php/files/45e5b77v2h3kosa1qtpo9uum84/zuferaxoxubizujuw.pdfIn PDF document text
    • https://www.djluk.co.uk/wp-content/plugins/super-forms/uploads/php/files/53v4k1vitnvd6618684svhmiec/jizenuxenifopiz.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/5sijb28e80abtdns5tvg633tga/66177220957.pdfIn PDF document text
    • https://brahmagnanam.org/fck_uploads/file/54004411653.pdfIn PDF document text
    • http://rokakisreunion.com/clients/a/a8/a85ca1e4cfc2bb88d767af442173b437/File/27405399897.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160931938df6c7---22073301242.pdfIn PDF document text
    • https://atcotourismtravel.com/userfiles/file/80073972990.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/728c56e0da8115636bcabd2ff486d62c/sipafepirogukibigov.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608541b64a9c1---87087778220.pdfIn PDF document text
    • https://lerong.vn/wp-content/plugins/super-forms/uploads/php/files/643d3fd54c9a92644b22ebe26e07367e/4549302135.pdfIn PDF document text
    • http://cy2hand.com/userfiles/62015238773.pdfIn PDF document text
    • http://www.yoko-ono.be/images/userfiles/file/25423974247.pdfIn PDF document text
    • https://laetitiabernard.fr/images/file/92053168351.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160984b18a2ea2---88848618609.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160bd448195f36---sulokubux.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d5791ef6da---47628449680.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160bc220c1c9ef---27898726976.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/potoruzexidu.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/b1bkp1usi5tu26nkur9ai5hd8r/kuxiforodefo.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b1a0d2694b9---53830485410.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=chat+amigos+onlinePDF link annotation
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED82 16748 bytes
SHA-256: d9d4581009e8136bed7bd389f7cb8058915c37a6ebc1deb04c4720d7dea2e498
font_01_sfnt_off000118df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118DF 10488 bytes
SHA-256: 9be9e61d396944aa35dead43330af3dd02bce2bace7682184019bab9193c36de
font_02_sfnt_off00013091.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13091 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1