Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7d21ad16c9c07a7…

MALICIOUS

PDF

98.1 KB Created: 2021-07-18 04:26:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7a6c29a527c58c7eede4659e679164fa SHA-1: 87e65f54e892bf0f61a0fe19442f2c844e29cd43 SHA-256: a7d21ad16c9c07a779157f8b608f3816a39946e172ddda44ab0e01a35a2b1d33
176 Risk Score

Malware Insights

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

This PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The heuristics indicate it functions as a link farm pointing to compromised WordPress uploads and disposable hosting, consistent with phishing lures. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of embedded URLs and link farm heuristics strongly suggests an attempt to redirect users to malicious sites or solicit fraudulent calls, aligning with callback phishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9928

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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://xanbiente.de/userfiles/file/dixidukojuv.pdf
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/943e860583215045fea97fa555d376d8/25801619341.pdf
    • http://majorsagilekvaros.hu/uploads/file/rotupe.pdf
    • http://glcore.net/ckfinder/userfiles/files/5868291758.pdf
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075708d14610---nelokup.pdf
    • http://vinhthuan.asia/upload/files/43196591970.pdf
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/89ef3ec0f7eaf84a83078fde74d727e2/12177617418.pdf
    • https://yssnewlessons.org/UserFilesTwo/file/wesesemizaju.pdf
    • https://bacninhonline.com/webroot/img/files/fazedefeximewozozo.pdf
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1606da3ac48565---38042475972.pdf
    • https://alarrabnews.com/images/content/content/file/66151079389.pdf
    • http://keramann.ru/uploads/files/37516872566.pdf
    • https://daquin-ferriere.fr/userfiles/file/ravixurifumelagum.pdf
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/aver641ipgluu1fn95cstr6778/nagumalozegimubexufuk.pdf
    • http://4reality.cz/userfiles/files/kovijadulutuz.pdf
    • http://chinalabware.net/d/files/xowebusan.pdf
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/fa2mcjg43s51sfq3puuunl8ce9/84739367720.pdf
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/160730e77d56cf---dupobalujo.pdf
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0977c9d2cf---50513751304.pdf
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/49poh6lqjclftblat13np67uem/nakum.pdf
    • https://hagepoorter.be/files/files/29916807471.pdf
    • http://hillcountryawningsandsunscreens.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fecf349b08---99607155750.pdf
    • http://www.findvoters.com/userfiles/file/bopuruwubilifupimanip.pdf
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/e8135e5999aa50892f1c663cc1aaad52/sudimajubewazewopatojiraf.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=bottom+growth+on+t+pictures
    • 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_off0001184b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1184B 16792 bytes
font_01_sfnt_off0001305d.bin
f9c01d00dcd0902d1a757871f8d434494aa16a9d8d79aec3e46931b387606775
pdf-font-stream PDF embedded font (sfnt) at offset 0x1305D 18284 bytes
font_02_sfnt_off0001609e.bin
878a8bc441188144344d2263dec1173fc5bfaa5bd3f307bdb4aaead52abd352a
pdf-font-stream PDF embedded font (sfnt) at offset 0x1609E 10852 bytes