Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5a657fbe5481568…

MALICIOUS

PDF

85.5 KB Created: 2021-06-26 17:38:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2399a35238420619a46c23854f3dcd75 SHA-1: 0531e3c721c1325976781998225eb7082a6d586a SHA-256: f5a657fbe5481568d20ef69ba79b2f0aa6eba88c9dc8de65c41c181c894f48c6
156 Risk Score

Malware Insights

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

The sample was detected by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised WordPress sites and other disposable hosting, suggesting a link farm designed to redirect users. The PDF document body is heavily obfuscated and unreadable, indicating it's likely a container for malicious links rather than user-facing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://atphp.ch/userfiles/file/jetezijadoxomozawuvid.pdf
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aad02247470---51974655882.pdf
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/4q0aa362kc41ojveiimt44l65p/67642023376.pdf
    • http://clairerolo.com/userfiles/file/gusefiw.pdf
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/4fa117a17b18b6f3134607adcce67341/22060343728.pdf
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/fm6h48cuh2a4fgjqiu931i6o4r/26297608664.pdf
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/1jkpcs949u8gsa9g8uv53p7ei0/xexamurevawamixi.pdf
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1607890c71fc17---73567428115.pdf
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160bbe06c713cd---jejijisulowod.pdf
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d5f7a792c2---zedulurapup.pdf
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee50d6716b---xodubimowi.pdf
    • http://xz-brand.com/ckfinder/userfiles/files/70407955817.pdf
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/61d21c1c860b7bef46e4c1c5037ad4a8/wefafas.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c475b19dff1---16145500627.pdf
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/16093cecbf07b7---50743832163.pdf
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/5b136cf60e8b296b9c2b4708bd037dc2/fasutexiro.pdf
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/80b6snpm7ln0at43g59ip6lqna/66300033373.pdf
    • https://sukhayurveda.in/userfiles/file/witozifofa.pdf
    • https://cls-toronto.com/wp-content/plugins/super-forms/uploads/php/files/73cfd7928ec512c4185936114f804894/1396840300.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=minecraft+castle+building+tips
    • 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_off0000ebe5.bin
81e2fcd7afe5a1e0417cf931630e85627239c0dce319deb077359a745885022a
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBE5 16864 bytes
font_01_sfnt_off000117d1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x117D1 16792 bytes
font_02_sfnt_off00012fe8.bin
24128a698305c0a1edd265ce9ae7e73a8ff4cf4efe320366b251d6416312e4e9
pdf-font-stream PDF embedded font (sfnt) at offset 0x12FE8 10908 bytes