Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f67b2ada8cccdb2…

MALICIOUS

PDF

82.2 KB Created: 2021-07-21 01:02:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a844420270776246fb2650690d41b3e2 SHA-1: 8b190bd4630a60ed850d3318f5503576497917f5 SHA-256: 4f67b2ada8cccdb2a2dde1c3e1910650a485e49c35b9e2c268066f9ba040c92a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by multiple heuristics and ClamAV as malicious. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of a phishing or malware distribution lure, likely delivered via spearphishing.

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://myucpb.net/userfiles/file/ribubegipuvuvewega.pdf
    • http://vladjurnalist.ru/archive/file/66979465356.pdf
    • http://inwallendorf.de/userfiles/file/62455669394.pdf
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a41c1d4c4da---sunoxowezofiro.pdf
    • https://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/c98a3bd5dc4ad620255ade1fe963683d/wanubufiwofunevo.pdf
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/kruvik56v2jhpjuhjqjslcjjpe/lixapat.pdf
    • http://abc-tel.ru/data/File/98904850540.pdf
    • https://groupunsur1.com/contents//files/18943796292.pdf
    • https://nanosoft.mn/images/content/File/josebefi.pdf
    • http://nhadatv.com/webroot/img/files/35164954911.pdf
    • http://vuatoyen.com/uploads/userfiles/file/rasamaxe.pdf
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/39790587701.pdf
    • http://skiflogistics.ru/userfiles/file/32568233056.pdf
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/d01ec972225febc5282fb9540b8ec662/77365130233.pdf
    • http://kaies.net/upfiles/file/37234038066.pdf
    • https://commonwealthsportsawards.com/userfiles/file/34931381259.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/o2istv3h371a47n1r9ucn7ei96/wosororinu.pdf
    • http://tpdw.pl/userfiles/file/64461754977.pdf
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/16087c8df247eb---tibin.pdf
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a48ac3bafe2---vetedalurubumevapep.pdf
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/7bdda1c62fc54bb65f8fa1925db300d9/13039498381.pdf
    • https://spheresignal.com/app/webroot/userfiles/files/29464283389.pdf
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/ob99b47indj5t5repia5ujdbkt/figepir.pdf
    • http://sacoorhealth.pt/site/upload/file/73940608300.pdf
    • https://gradeagroup.com/wp-content/plugins/super-forms/uploads/php/files/nofj0efim7o61qaodghvq1f89s/vusuditagonowaka.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=noble+gas+notation+for+iron+iii+ion
    • 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_off0000dc6e.bin
387517e981f5a664d3d27ad70dd03d8ee9bd0259193ac8dfa643b239318ee9d4
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC6E 17704 bytes
font_01_sfnt_off00010b1a.bin
e9d87daa4f3bf248363ce4cd1c2daa43479f46ef1efed010350890adc11a4fde
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B1A 10504 bytes
font_02_sfnt_off00012326.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12326 16792 bytes