Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c583c72470e581e…

MALICIOUS

PDF

73.4 KB Created: 2021-10-18 18:23:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: bc5252dd2524a64d7c4f71898719e283 SHA-1: 5943636922c893e3ec85b6209b9283f19aad0953 SHA-256: 0c583c72470e581ee3b28a9c4f9b0b0d4ac69e05ceb3b7c531d921293fa96eef
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised websites or disposable hosting, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be generated content rather than user-readable text, further supporting a malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://catamma.ru/uplcv?utm_term=how+to+draw+derivative+graph+from+original+graph PDF link annotation
    • http://elmbbq.com/uploads/files/rileriwabinojeb.pdfIn PDF document text
    • http://devveb.net/userfiles/file/sebekelukazowobo.pdfIn PDF document text
    • https://relaxbotanika.cz/ckfinder/userfiles/files/puzudipezukexulok.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/6b41ebf2504cd51bcfaca747b72a5c1f/mopevolozasetusoja.pdfIn PDF document text
    • http://sayarbobinaj.com/file/45388781003.pdfIn PDF document text
    • http://fizjoactiv.eu/Upload/file/94983777594.pdfIn PDF document text
    • http://freewest.at/soseriwuv.pdfIn PDF document text
    • http://euroambulans.pl/userfiles/file/gazodoj.pdfIn PDF document text
    • https://masukpt1.com/contents/files/sarosipozurojari.pdfIn PDF document text
    • https://htlexpress.com/ckfinder/userfiles/files/godememekelejisozev.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16153d4a17f52f---ritugi.pdfIn PDF document text
    • https://vmgeducationtrust.org/home/vmgedu/public_html/public/userfiles/file/lomer.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1614c44a6654d7---tobunokumef.pdfIn PDF document text
    • https://kar360.com/resimler/files/19222549452.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1614d9ffac521d---vusifigonudejoduvaz.pdfIn PDF document text
    • http://bkht.vn/userfiles/file/33582488680.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/f501b400219205f6f184bba39cf4ab6f/xeragufexofotadadosa.pdfIn PDF document text
    • https://dalycity.com/wysiwygfiles/file/89433819122.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/48983292654.pdfIn PDF document text
    • http://applecentervn.com/uploads/image/files/sabetogomijorelezafoz.pdfIn PDF document text
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1616c79ebb407f---fekexutuwibigisivikuwekeg.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bb8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB8A 16932 bytes
SHA-256: 387dae1d2a5ce50e6ba27689494248c9596c0bd326937e01a7fa878a730dc63a
font_01_sfnt_off0000e6d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6D1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fee8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEE8 10920 bytes
SHA-256: 3db88a592ab17b001dd1d3358afbf35ff447d9ec6a35fceac80464af08c18ea8