Malicious PDF — malware analysis report

Static analysis result for SHA-256 898ae9f2a61b3120…

MALICIOUS

PDF

85.0 KB Created: 2021-06-25 17:55:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 098f9ecb2d5738517b9702e6c063d615 SHA-1: 0ebc8b4d7f3297304c7ec75c307e10e5d1d07603 SHA-256: 898ae9f2a61b3120dc5288d468df8131bda1d09713283f9e3c5cf5d1c3c9e2ec
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous domains, many of which are hosted on compromised CMS uploads or disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. The file's structure and URL distribution align with common tactics for initial access via spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://cuatudongsaigon.net/uploads/files/11046338040.pdf
    • https://appvid.eus/userfiles/files/13781079729.pdf
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/531d169cf5d30b09fa8de14f7a09bce1/26050760673.pdf
    • http://bulmarconsult.com/files/74169672478.pdf
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a14324dde31---rumukudib.pdf
    • http://sip7.online/wp-content/plugins/super-forms/uploads/php/files/47780f4053052d601c17131308c9573d/jogozibesijupim.pdf
    • https://stpeterscbs.ca/ckfinder/userfiles/files/bizixozo.pdf
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/ebonfdhmb4qq99qa05ffpl47ua/23174641791.pdf
    • https://noithatkuongthinh.com/uploads/files/bokewaxepo.pdf
    • http://dok-vo.ru/userfiles/file/lavesuj.pdf
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/15968466410.pdf
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c037cbbcc66---5713122583.pdf
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160710c0ed9476---kutabeworateduf.pdf
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afd8b33acdc---xixipapebixineneruxisam.pdf
    • http://ciccioinpentola.com/userfiles/files/19689142614.pdf
    • http://amexeuro.com/an3_Uploads/file/36178322090.pdf
    • http://alkanboya.com/files/file///xogipimekikav.pdf
    • https://a2designbg.com/userfiles/file/91344981085.pdf
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/4e7a12b0200f3bca624e63d73e7a57c3/56660935075.pdf
    • http://bmhs1963.com/clients/7/72/7286fd37811b7a5dece6e69924e4d5ab/File/22654660631.pdf
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/5ab7575ec933634b61ee5fbf879c4346/91076681612.pdf
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/fa91uhf6e30d176075f65gpvg2/pesejopoxo.pdf
    • http://unicorn-furnitures.com/d/files/doxesikujo.pdf
    • http://alpanelektrik.com/depo/sayfaresim/file/maxasemimoboserem.pdf
    • https://amblamy.ee/upload/file/tetuxalagokep.pdf
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/0od9n2enoi27iqi8qr6bci2mad/duzapojivejalasixiv.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=student+atlas+of+world+geography+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_off0000e76c.bin
c7c34b444464e2581987c8571f5f969413ace47bf5b2b7631abec1b3c50765cd
pdf-font-stream PDF embedded font (sfnt) at offset 0xE76C 11060 bytes
font_01_sfnt_off0001010e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1010E 16792 bytes
font_02_sfnt_off00011920.bin
6f49d70886693a91543fa58c50d421c16dd3fc2779662c774df9bdd7b893ef90
pdf-font-stream PDF embedded font (sfnt) at offset 0x11920 17336 bytes