Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f6cd89dd7d4335b…

MALICIOUS

PDF

72.9 KB Created: 2021-06-30 02:27:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9f73da0548d95308cc7c57c27745727f SHA-1: 07e51783ed6a9c896fd13df9715faa5835f4183f SHA-256: 1f6cd89dd7d4335bf73ed0378abece24af64be45cfbb8317d43d30dd7ff88a48
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, pointing to numerous compromised WordPress upload directories and other potentially malicious URLs. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://orrizon.ru/images/file/59300077144.pdf
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bce95e91f9---58336962783.pdf
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e19de5d9e9---lumavub.pdf
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1609e2c3121323---xonoganila.pdf
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160b5c06d2fa63---98186894870.pdf
    • http://bazis-expertiza.ru/ckfinder/core/connector/php/files/6142632622.pdf
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4da982e496---91611568572.pdf
    • https://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/3678ca7ba1ccf991b5f3e1ae0956caea/65026572465.pdf
    • https://hoongnau.com/upload/files/11668338638.pdf
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/fb4d8e968350455edcca896348bbf294/80115165157.pdf
    • https://travelstore.tn/userfiles/file/zomujezolivoviniwevofux.pdf
    • http://aelma.com/sites/default/userfiles/file/45844339719.pdf
    • https://traonguoc.vn/wp-content/plugins/super-forms/uploads/php/files/dfflb7df41hmog5rqeb91ripnh/27915044033.pdf
    • https://arhometutor.com/userfiles/file/gusevetit.pdf
    • https://nutricionintravenosa.com/wp-content/plugins/super-forms/uploads/php/files/c99cd6f54572bb6591c40c2d57d273cb/kovekakerimoxugofogadaf.pdf
    • https://condicionamentofisico.com/arquivos/file/rukemimaja.pdf
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/54510f8e87e6b7ef0688dd7683fe4504/jupuxasuw.pdf
    • https://banghenails.com/upload/file/tulanikigufifozog.pdf
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/1e6c700fe350d96da7b2901479e59705/72317144546.pdf
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/kdtt3tk0liu3kicn6ke6p221e4/fozolakagupusefaju.pdf
    • http://bearings-home.com/userfiles/file/17673059545.pdf
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/df0d43d6f80c03f351360f82c1c14969/43405656510.pdf
    • http://morard-mcf.fr/data/Files/14350175816.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=types+of+water+treatment
    • 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_off0000bb6d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBB6D 16792 bytes
font_01_sfnt_off0000d37f.bin
dcbb6868ce00ae5251ae4ad2d38198d2f5cfbca2d31331e71a790376e0d8eebb
pdf-font-stream PDF embedded font (sfnt) at offset 0xD37F 16536 bytes
font_02_sfnt_off0000fe58.bin
ebe3a476e53d26bed874c097492ff107c66d2e9df56d1a008eac7ae2292b1a77
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE58 10544 bytes