Malicious PDF — malware analysis report

Static analysis result for SHA-256 85e50a80a22f8e91…

MALICIOUS

PDF

84.2 KB Created: 2021-08-19 08:32:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f6182202ace20c9349a3fe21187ac227 SHA-1: b7fe1edf409ff67adf062a207497a5ddaa8e7cb7 SHA-256: 85e50a80a22f8e91387b688edbdf82c9230e11691c5cfc793f99557482393e22
164 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm pointing to compromised CMS uploads. The PDF likely exploits a vulnerability to execute JavaScript, which in turn redirects the user to one of the numerous URLs, potentially leading to phishing or further malware delivery. The presence of multiple distinct hosts and the use of 'utm_term' in some URLs suggest a coordinated effort to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://korealabels.com/ckfinder/userfiles/files/53743913151.pdf
    • http://changdahk.com/upload/suzolezezegevuzebi.pdf
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae9a0825929---rorugalifaregiberulomaw.pdf
    • https://cartolmania.it/file/19693978816.pdf
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/0lf4kn0qnsvsdeih2vhabcbgmc/66500586233.pdf
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160ec4fa6e5461---49731479981.pdf
    • http://autosvanbeek.nl/mindcms/js/ckf/userfiles/files/dinovug.pdf
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099c21e5e2c7---bonupugekabawe.pdf
    • http://tt-ural.su/admin/ckfinder/userfiles/files/88561179565.pdf
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a4bddbe45d---duvumasuk.pdf
    • http://hoanggiaphatstone.com/upload/files/vigaxetizadotezurekilodi.pdf
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/ef33c682894243e7b5d62b8377832192/60940059427.pdf
    • http://wingprocess.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/43469741046.pdf
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083c38d74c36---fanugofigasox.pdf
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad3ccb2fc1a---26970685567.pdf
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/75nvmau7c63qksdft45v5k0pf5/47887591647.pdf
    • http://teusz.pl/UserFiles/file/tafetuwopowisetaj.pdf
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099aceb5be36---63566918035.pdf
    • http://xn--365-pn7mwb654m2qn.com/ckupload/files/kagawifax.pdf
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b9aa063f830---milafix.pdf
    • http://ministerium.pt/files/pozogadamudu.pdf
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606caefbd7441---kilod.pdf
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/6f3684060671c96fa87b204a2cdd2907/26117751640.pdf
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd0ca8eb606---48810325949.pdf
    • http://namlongprojects.com/images/uploads/files/47405982632.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=factors+and+divisibility+calculator
    • 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_off0000e766.bin
b986ee8bbc6b55e8b31073561e8863ad7b7257ef30a9bfd35c7ac4ae858ddc17
pdf-font-stream PDF embedded font (sfnt) at offset 0xE766 16656 bytes
font_01_sfnt_off000112d4.bin
d6d63202f49dc580de51c83d6a09862e6546bffbb492a9ce1f18d3227d048ebd
pdf-font-stream PDF embedded font (sfnt) at offset 0x112D4 10628 bytes
font_02_sfnt_off00012b49.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B49 16792 bytes