Malicious PDF — malware analysis report

Static analysis result for SHA-256 8add99de55d7858a…

MALICIOUS

PDF

88.8 KB Created: 2021-06-25 21:08:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 26828808eb9f4613d6730384059a7d11 SHA-1: 4a6fa8211dbf29ea062616bb12a4f6fd65b48265 SHA-256: 8add99de55d7858a6c9a217f5d8eb65de6c0bae06382c89f9f00f554a7b280f4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The presence of 'utm_term' parameters in some URLs suggests an attempt to track user engagement with the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f45fee9d3d---9500097505.pdf
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/160883897c1eee---66356664184.pdf
    • http://aire-limpio.com/img/editor/file/51450265797.pdf
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1a22c8fd5d---linig.pdf
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160860a05b4784---80796788181.pdf
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/2up8q2u1jr6ludm2rujj992nea/vijozolojamixetovuxubita.pdf
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/71d2216616a973a171485e14d77719d9/livujuzonilafopog.pdf
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a250ad1fc52---divaxunu.pdf
    • http://lawngo.net/fckfiles/pusimexetanirusot.pdf
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/bbbf3f73abe5eee9e088abfba39f630d/35412232131.pdf
    • http://stepsforstarlight.org/clients/c/c6/c668404594a1c08d975ab50c7bec58f6/File/fipibatukepugogarex.pdf
    • http://itssilvertime.com/clients/2/24/24efe347a73a8ce028152bf895bc11a7/File/ridar.pdf
    • https://humble-brag.com/wp-content/plugins/super-forms/uploads/php/files/d89lfphtkcnphs4oktfqt173ul/82253863192.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b6263747e39---kopibidinezugodep.pdf
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a38911230dc---86155571759.pdf
    • https://brianhigbielaw.com/UserFiles/file/lasurovubanofup.pdf
    • http://abacusnancy.com/userfiles/file/mugelu.pdf
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f44c52c4b9---vijadowel.pdf
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608efea82fec7---dabasenejigikujegeku.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7abe8d7eb2---pojuka.pdf
    • https://hgb.se/filer/file/goxamipax.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=when+question+and+answer
    • 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_off0000f8c1.bin
7f4c9d682ac618e6694edba01f6559195fa8b4b602cc15d9c22e057dbb9dcd52
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8C1 17288 bytes
font_01_sfnt_off00012607.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12607 16792 bytes
font_02_sfnt_off00013e1e.bin
fcc14509aa0fde9c738a5ceefdd6c60825b9d1f98c09f97a28f06a07821b66ce
pdf-font-stream PDF embedded font (sfnt) at offset 0x13E1E 10624 bytes