Malicious PDF — malware analysis report

Static analysis result for SHA-256 21cb2116e106f8d5…

MALICIOUS

PDF

89.2 KB Created: 2021-08-18 15:05:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5803e8c585ae1ce2618b7fd006813bc2 SHA-1: 275c402821d89d65237c20ee44e1b4ec27ee4772 SHA-256: 21cb2116e106f8d515d52ef2612205cd1ad91685afc6c781ed4516e95bd5b7eb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or trojan threat. It contains numerous external URIs and link farm patterns pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, but the presence of embedded URLs and the overall structure strongly suggest a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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://nomylo.ru/uplcv?utm_term=watch+dance+moms+season+7+online+free+123movies
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160faef24c0e73---63345175564.pdf
    • http://bloemenwinkelindex.nl/images/uploads/12206319927.pdf
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/9a4gq2ij6fu8edll59m1mrlr50/45613783790.pdf
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7b6bf1eb85---92294806441.pdf
    • https://jambukuning.com/contents//files/10691831373.pdf
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607255d153a35---dudetuseleduzuzivoloxiso.pdf
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/4e7b94af6070937fc432a0fc8f8d7a8a/pojot.pdf
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/16094d829cdb1c---zakiporawifabev.pdf
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/76325444806.pdf
    • http://ruishikaishi.com/upload/content/files/2021/07/20210727054235.pdf
    • http://15449010.com/FileData/ckfinder/files/20210808_17408154C6E08223.pdf
    • https://mgs-on-track.com/uploads/misc/files/79270143962.pdf
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/453574e3e6ff3fdbe856855066d5c5a3/4674758808.pdf
    • https://mytalk7.com/_UploadFile/Images/file/11701459679.pdf
    • https://stallion-international.com/userfiles/file/50667492414.pdf
    • http://williamshudson.org/clients/3/35/35bf74ce48b5c120232fd40fb4fe3e45/File/56957519946.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160abd9ed7e627---44913745008.pdf
    • http://newtarrytowndeli.com/uploads/files/83200073058.pdf
    • https://tinnituskozpont.hu/files/47384339026.pdf
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/b09597b85923b8728bc03693518f8f0b/tilibotukusavinawuxoriwul.pdf
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/51129235202.pdf
    • https://kientrucqhouse.com/uploads/image/files/wukavoloka.pdf
    • http://alimentosldm.com/userfiles/file/74561852468.pdf
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abd66507d47---21949381994.pdf
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b4091c97b73---19807830719.pdf
    • http://agro-vostok.ru/userfiles/file/47631862031.pdf
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/16091a3ed9dc3f---10352750562.pdf
    • 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_off0000f65a.bin
be10ce06109b361f141e203266add385abb7056dededd019ff0c917e974248bf
pdf-font-stream PDF embedded font (sfnt) at offset 0xF65A 17612 bytes
font_01_sfnt_off00012485.bin
e0df1ecbc8d76448c221145b6951be95034f4e344aa0f7ea1669cd3f80eea543
pdf-font-stream PDF embedded font (sfnt) at offset 0x12485 11196 bytes
font_02_sfnt_off00013eb9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13EB9 16792 bytes