Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c155e21d8cf2538…

MALICIOUS

PDF

68.0 KB Created: 2021-06-19 01:48:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: f9dc624472d6fcc8dbcbbd5bcbfaf8ab SHA-1: fab9d9f94814d83cf0f19b0ee24f68c034866b27 SHA-256: 1c155e21d8cf2538009241c390d0dcbe19242cf584e7f8f15e26052c64e2b2ea
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a common tactic of distributing malicious content or redirecting users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://synerhu.ru/uplcv?utm_term=class+9+maths+chapter+1+worksheet PDF link annotation
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c23cdab0d26---31217307710.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/u3lafk71vq95hbvk6686noecu4/buvujowebuduzawuribumelo.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf04d66d15a---tusamugewapapa.pdfIn PDF document text
    • https://luminex.pl/upload/file/78308680067.pdfIn PDF document text
    • http://alliance-ltd.com/userfiles/kexaji.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a62cafbe9ee---96966165518.pdfIn PDF document text
    • http://parcfamilyreunion.com/clients/b/b3/b3ae52aef0329bb57e848b27182677c8/File/xifajomarubaduvezozuwe.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab0895a7de6---86809934634.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/59f088d2ac9b89cd3bb284aaa8c82c8e/38048447048.pdfIn PDF document text
    • http://learnersdigest.org/userfiles/file/26636196380.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/f99d3eaae60e9bf7e04d52e2693f8594/xofopemi.pdfIn PDF document text
    • http://stallingreunion.com/clients/a/a3/a37dbb3dca22f8cb40f44de83fe48269/File/gugozojigikoludiwe.pdfIn PDF document text
    • http://www.homefacelifters.com/wp-content/plugins/super-forms/uploads/php/files/05b47306091827a318ac2dbe8e73662c/zipojepabubimez.pdfIn PDF document text
    • http://srihemkuntschoolint.com/slbdavbatala/userfiles/file/94142816228.pdfIn PDF document text
    • http://morethancars.nl/uploads/edytor/file/88536502714.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/6mr2n8p7bqkidmcahdlkskr076/pafumuxuvizukiz.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c6c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6C5 5440 bytes
SHA-256: 8d4fbcec982dcae60e5112bc2f6c6580f421212323e82a2be4d6834c01e280f8
font_01_sfnt_off0000d92c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD92C 11800 bytes
SHA-256: fada4343fab47c19a7c7572d5cb1ce6308a1530295e882b6efa00d784c08a4e5