Malicious PDF — malware analysis report

Static analysis result for SHA-256 9821a61990c338da…

MALICIOUS

PDF

70.7 KB Created: 2021-05-10 08:05:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0f63af848725babacfd6800b1d8fbc77 SHA-1: 644926050e25f46872b5d1cf42ad8db62de2cf76 SHA-256: 9821a61990c338da03853c6e75d358a62eba504d0e83f89e3a90f516454531a9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, but no clear textual lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/5uq7db22ea11lklnspespsiagc/wunipovikeganuvoradupuma.pdf
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1608a5e0d8d9d5---96063708603.pdf
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/9f97cf146ed989af87a8c212aa079d45/rogasepibene.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082b95608064---28440853517.pdf
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160967b0f454bc---35780415626.pdf
    • http://www.molinoag.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081ec82cd7d0---jonukamuvajaluzilebobi.pdf
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607c6e9c1c987---weranizalenisewedaribebe.pdf
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608a4c0d34531---83441327668.pdf
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7943c56c0---pazefudefodus.pdf
    • http://staging.impactredevelopment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607249e8b392b---migumalexa.pdf
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c82feb9390---62713819225.pdf
    • http://aldara-latinoamerica.com/userfiles/file/39326001280.pdf
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/s6t9jsftln18ei03aem8sdck3e/363801215.pdf
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160975d9a82b6f---33661503134.pdf
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/uit1n3jugfqbvu5k785flhkh5e/xupozaxop.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/16097e674c0df6---sodukagamotanisi.pdf
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/16085496e5305a---54114868988.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=emery+cloth+sheets
    • 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://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cbe7.bin
e45f44b254a84100a280be726c7665b068e42ea91ed3d24b80e0fcb424f17583
pdf-font-stream PDF embedded font (sfnt) at offset 0xCBE7 4520 bytes
font_01_sfnt_off0000db44.bin
77e49cd00e8fc0614cb9bf78a5253ca69428e3ada4aa8e7f081f02e30dd01343
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB44 10728 bytes
font_02_sfnt_off0000ffcd.bin
a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFCD 4324 bytes