Malicious PDF — malware analysis report

Static analysis result for SHA-256 84a22a56d39c95aa…

MALICIOUS

PDF

69.2 KB Created: 2021-09-28 04:22:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 83b58f5dfdb8044399cd415deb87815e SHA-1: c3a738165a61a30d7c8fadc7a381aef2701745c3 SHA-256: 84a22a56d39c95aa6d27ec64f529038d9cb6ef1dbf0e0869d5bf5d6472d31846
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to compromised or disposable domains, suggesting a link farm designed to redirect users to malicious content or phishing sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically highlights this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 https://synerhu.ru/uplcv?utm_term=how+to+install+iso+file+in+android
    • https://ritascreation.com/userfiles/file/48339061436.pdf
    • http://freewest.at/77069177383.pdf
    • https://sensiblemachines.com/ckfinder/core/connector/php/files/zixovelezumoduzikodisevop.pdf
    • http://salocchi.it/userfiles/files/33173213314.pdf
    • https://adeptos.clevercloud.pt/images/items/files/5404041632.pdf
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea45a1b0de---silurenozugo.pdf
    • http://nanobubblevietnam.com/uploads/userfiles/file/vulezuv.pdf
    • https://decoveinvestment.com/userfiles/file/kepamezum.pdf
    • http://rudolphi.nu/userfiles/file/wemowonax.pdf
    • https://timminsrenovations.ca/file/IVIgUiW876b1hUIQ.pdf
    • https://permargi.com/files/galeria/files/72520179542.pdf
    • https://ekinyalitim.com/depo/sayfaresim/file/1466910835.pdf
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161339d7509d21---gejifelowizovosabifuwu.pdf
    • https://0955205219.jwa.tw/userfiles/files/lixanivado.pdf
    • http://9jamail.com/FCKeditor/editor/filemanager/connectors/userfiles/file/zugijizoli.pdf
    • https://mimpi1pusat.com/contents/files/73150393181.pdf
    • http://travelcenterpuntos.com/campannas/file/zalodaramivexusat.pdf
    • https://vr-spagna-20.effievirtual.com/galeria/files/59911977334.pdf
    • http://mrrb.nexgendevgroup.com/files/84245056854.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d6c6f5f758---rowozejarojojovugok.pdf
    • https://jdrum-music.com/uploads/ckfiles/files/solunesekubibuki.pdf
    • http://fueandhair.com/userfiles/files/wutep.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_off0000ad48.bin
9c49c16ad787398fd5ba1b7641d24d8d656e24720d5789c2c3abcae035565601
pdf-font-stream PDF embedded font (sfnt) at offset 0xAD48 10424 bytes
font_01_sfnt_off0000c50a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC50A 16792 bytes
font_02_sfnt_off0000dd1c.bin
a208331f3daaf6d1c44f64c9aed71c7d2ba7e1cc805fb9cb31b1e0223233b898
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD1C 16856 bytes