Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b88cb86838e4132…

MALICIOUS

PDF

83.4 KB Created: 2021-08-20 17:06:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7b3bddba9782b18aedf596463442d695 SHA-1: 53af605d630f168b27ff853b4a3bc9ad6703ade4 SHA-256: 9b88cb86838e41328b28aae38b1eaf8fc992949db2f61ac07a731f1ed66df528
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains numerous embedded URLs, many pointing to compromised CMS upload storage, suggesting it functions as a link farm to distribute malicious content or conduct phishing. Although no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics indicate an attempt to redirect the user to external, potentially harmful, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/68b32ebcb674cfc72c9ca8005178ed70/43269043370.pdf
    • http://erdivigado.hu/userkepek/file/puteri.pdf
    • http://diversecityuk.com/userfiles/file/tined.pdf
    • http://sinsg.com/files/fckeditor/file/37247399881.pdf
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b76d5eb7ebb---97282607277.pdf
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/23099249d908e3dec723065b9f0337b8/pujobafeleziloti.pdf
    • http://bamor.org/userfiles/file/nobinakulajixugibib.pdf
    • http://plnjl.com/userfiles/files/39619231005.pdf
    • http://studioguatta.it/userfiles/files/20520746175.pdf
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/tdq1n2dbqcq42hkthl3auci5b3/62485688813.pdf
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/4dqha5mdh6ol2l978bda8kg7jh/sepidoneg.pdf
    • http://phuclocvienjsc.com/uploads/image/files/79613914409.pdf
    • http://dermatologomiguelgallego.com/miguel/fck/file/mikaxotanagukilik.pdf
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a847713837---supanobuxelavu.pdf
    • http://maduraigarlandshop.com/userfiles/file/moruse.pdf
    • http://akekaluck.com/ckfinder/userfiles/files/16555373183.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609aa8f7c8cb5---rakoropuguzorolisizejune.pdf
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160829daa36281---lujimep.pdf
    • https://fundacionamigosdelmarcaribe.ong/ckfinder/userfiles/files/jezale.pdf
    • http://chatfieldfarms101.com/userimages/78470648688.pdf
    • http://scouttautomotive.com/editor_uploads/system/files/52137268042.pdf
    • http://porpora.info/imagenes/imagenes_contenidos///porujafitodiwelijamib.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=can+you+download+roblox+on+amazon+fire+tablet
    • 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_off0000e0c4.bin
368e5b266eb495248ae30fd0d8b4e31b36f02264620b582edc1f176cf1d0ac7f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE0C4 16888 bytes
font_01_sfnt_off00010cec.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CEC 16792 bytes
font_02_sfnt_off00012503.bin
79f2b7368322ea11b9c6cdfe46ea5179bdc09193a26876d7af0c5533b2d730d5
pdf-font-stream PDF embedded font (sfnt) at offset 0x12503 10980 bytes