Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c16eff19a8313b5…

MALICIOUS

PDF

83.2 KB Created: 2021-09-16 17:16:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b25d7948d48ab0468684c89aea08df77 SHA-1: 910250fcf69c14fef1329ee55b96346209a0863c SHA-256: 3c16eff19a8313b5f8f25c9ab836e81d7fd6216a3520dba3a81ef22dec7c0fde
126 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, with heuristics indicating it functions as a link farm. The document body is heavily obfuscated, but the presence of numerous unknown URLs suggests a redirection or download mechanism. The primary attack pattern involves directing users to a network of potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://musiclivemarsala.com/userfiles/files/nalejadef.pdf In PDF document text
    • http://all-premium.com/user_file/files/14154318008.pdfIn PDF document text
    • https://habibitoursegypt.com/ckfinder/userfiles/files/90335191085.pdfIn PDF document text
    • http://pbpharm.com/upload/files/moxasazedesiwi.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/rigebukew.pdfIn PDF document text
    • https://bnbtravels.com/ckfinder/userfiles/files/zuvowafopuwej.pdfIn PDF document text
    • http://cpviettin.com/upload/files/kosij.pdfIn PDF document text
    • http://tentauto23.ru/ckfinder/userfiles/files/67379544277.pdfIn PDF document text
    • http://elitaliaweb.it/upload/file/9171897891.pdfIn PDF document text
    • http://suvenirzp.com/uploads/files/fepapinufipebilotojisuz.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e55978fd8f---kexowimaxixilirafi.pdfIn PDF document text
    • https://renewone.de/files/rogaroxewalebogodas.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613882d3ed0cb---32518770326.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/7143438316.pdfIn PDF document text
    • http://japhina.com/upload/file/warisix.pdfIn PDF document text
    • http://relaxbotanika.cz/ckfinder/userfiles/files/zowowedi.pdfIn PDF document text
    • https://soccerauquebec.com/userfiles/file/77836609292.pdfIn PDF document text
    • http://travelcenterpuntos.com/campannas/file/giwezopanino.pdfIn PDF document text
    • https://nnt52.ru/userfiles/file/milapa.pdfIn PDF document text
    • https://xn--23-6kci4asohe8k.xn--p1ai/userfiles/file/lisolakorezeru.pdfIn PDF document text
    • http://ingore.cn/upload/files/lunaveken.pdfIn PDF document text
    • http://humansharehouse.com/userData/board/file/12947351041.pdfIn PDF document text
    • https://isuzuphonoi.com/data/dulieu/files/50283572511.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=sms+contacts+backupPDF 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_off0000df2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF2D 10572 bytes
SHA-256: e5e1eeefdc4a1d4078075ae6baaa9c585020a2a9b0b63fc2d3bc07cd68c2cac5
font_01_sfnt_off0000f71d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF71D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F2F 18540 bytes
SHA-256: e11108e38222d7bc736fffe895929027023a0902429a80cede94337ffe0164f2