Malicious PDF — malware analysis report

Static analysis result for SHA-256 79f03e39d34ff3ce…

MALICIOUS

PDF

83.7 KB Created: 2021-06-26 12:31:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6568c9d7d92a7b2dce7ef2789e9eb232 SHA-1: c9658e311c513a6e947ae543bd47a64530341d86 SHA-256: 79f03e39d34ff3cea05f09e66caf655ebea89b648435db5d53687813b494e0bb
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware. The document body is heavily obfuscated and unreadable, preventing a more detailed analysis of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 6

  • 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.
  • 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://atx-stroy.ru/wp-content/plugins/super-forms/uploads/php/files/783f7538fa4d27c1cc77c775d9516e12/gisividilap.pdf
    • https://kodcomputers.ro/2664/uploads/41450640596.pdf
    • http://jamessham.com/admin/usercontent/file/91616096082.pdf
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/6ghn79c7pis9g718c7knsnba48/vulusuzajisulali.pdf
    • https://coevent.ru/upload/files/85771245176.pdf
    • https://iominneapolis.com/wp-content/plugins/super-forms/uploads/php/files/9840912eb4fc12811d5a27c496c012c3/solasul.pdf
    • https://thewaves.net/wp-content/plugins/super-forms/uploads/php/files/9mim0lvi0cfopt013thcf4apc2/18495433427.pdf
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/c7d6fcbe0ab891cb2632bd86c513fd43/9647938429.pdf
    • https://universal4shipping.net/userfiles/file/35805131449.pdf
    • https://pcstaiwan.com/ckfinder/userfiles/files/daxubinilu.pdf
    • https://corpusbg.com/files/fck/file/57520264051.pdf
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/dbgmggbjg6e3akb40usq2brqn4/90518515930.pdf
    • https://xanbiente.de/userfiles/file/vunibuxe.pdf
    • http://biosafety.biz/ckfinder/userfiles/files/zevubij.pdf
    • http://uniquecharacters.com/upload/files/kofufap.pdf
    • https://aspaeng.com/files/image/files/2427592848.pdf
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/38eb295d319292bc9a4dfb7f9d152172/bumazebuzabexotemu.pdf
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609f2567c1a8f---jesawapamefidakorufevo.pdf
    • http://logisticsnetworks.net/ckfinder/userfiles/files/72282451192.pdf
    • https://autotronics.vn/userfiles/file/sativofalijagin.pdf
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075b21f1392f---gasidatomosex.pdf
    • http://bukharaatlanta.com/sites/default/files/file/tanezisunow.pdf
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea987ea770---17560211862.pdf
    • https://ccveg.org/wp-content/plugins/super-forms/uploads/php/files/larj6t6e2gv3qg2dilnqt5prn0/xisore.pdf
    • https://yourlightingbrand.com/wp-content/plugins/super-forms/uploads/php/files/ad4064382b717261feb8e4713371901b/fuxobe.pdf
    • https://www.autodepotperformancegroup.ca/wp-content/plugins/super-forms/uploads/php/files/ap2v659ml95s7mti85c1ehtcdj/fisokixusilekogad.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=ict+management+meaning
    • 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_off0000e7cd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7CD 16792 bytes
font_01_sfnt_off0000ffe4.bin
92f5d20741f417cb932ff701a7075f6f160da1a03935f34398c5c92d8a5d3640
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFE4 10088 bytes
font_02_sfnt_off00011657.bin
2a31df2d80adca97f887a7e7831118d972130d4682028172f03834ee21c64df2
pdf-font-stream PDF embedded font (sfnt) at offset 0x11657 16600 bytes