Malicious PDF — malware analysis report

Static analysis result for SHA-256 54f3bb9306b5c626…

MALICIOUS

PDF

83.8 KB Created: 2021-07-13 08:05:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2dadbc4b58c55e2eb7b1b57852396617 SHA-1: 386c4d592feb1f90c4350a6232cd97edf6384ed3 SHA-256: 54f3bb9306b5c626e6c2c2fe3b44807b605acc27c58f550734c34e910d28ca23
156 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs that point to various websites, many of which are hosted on compromised WordPress installations or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings and URL analysis confirm a link farm designed to lure users to potentially harmful sites.

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://inwebjor.ru/uplcv?utm_term=what+colors+do+you+use+to+make+brown PDF link annotation
    • https://topinsolventa.ro/userfiles/file/melitomijosewasazibota.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c328248ff6c---wuwofufodufawadofetag.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b5af418d7d---rebizalasilavenu.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084a577601e8---44958922510.pdfIn PDF document text
    • http://111-orte.de/testarea/cwsCMSlight/media/files/vajipumodazuvu.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16093bba70b489---vuvajewegemanoz.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/1607c607910439---guxisukinapapi.pdfIn PDF document text
    • https://almuhja.net/ckfinder/userfiles/files/89938547579.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607562996d912---15614893408.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160c182344af75---kepilopusotiralavolerulaf.pdfIn PDF document text
    • http://tourister.kr/userfiles/file/basupejud.pdfIn PDF document text
    • http://enricobarraco.com/files/sisorovavu.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/lfq3voio5540og5d2ckcinh1qk/5446709732.pdfIn PDF document text
    • http://hifi-markt.org/kunden/kronhardt/ckfinder/userfiles/files/zekemisuwabenuxifaben.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b00609754ab---46910622544.pdfIn PDF document text
    • http://hkacca.com/userfiles/24539041136.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/6uqa1pflg3c1rivpvfkuona5b4/78878221828.pdfIn PDF document text
    • 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_off0000e569.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE569 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fd7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD7B 16604 bytes
SHA-256: fff7bfcc47139f8db1d18e7894c74f3aac02f102e38c0dd45f85d02691213095
font_02_sfnt_off00012888.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12888 11068 bytes
SHA-256: 6e201044e71d59c388ab01fafb46e77cb01a719e62061b8b70d95a12e0c42fab