Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef5b373ff36d56b9…

MALICIOUS

PDF

73.8 KB Created: 2021-06-19 04:00:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 33795af9c3700202fd2a6fe7281ef368 SHA-1: 6df55806c23d9894561b1b1118c6edd73f8d4f0f SHA-256: ef5b373ff36d56b9e93627f1993f9d7cc4066c18893c9c554f0ba9b7313dd601
156 Risk Score

Malware Insights

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

The file is identified as malicious by multiple heuristics and a machine learning classifier, with ClamAV specifically flagging it as Pdf.Phishing.Trojan. The presence of numerous links to compromised CMS upload storage and disposable hosting suggests a link farm designed to distribute malicious content. Although no scripts were explicitly extracted, the PDF structure and URL patterns are indicative of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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.swissfillon.com/wp-content/plugins/super-forms/uploads/php/files/7372e8c34ac93e319630cc3292381907/77438874741.pdf In PDF document text
    • http://massageindex.nl/images/uploads/3477682640.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/ht7e5hfnme6tc75orgnrp9ub2c/bubelidolexakagolet.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b935fc70f49---80259579904.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160879df8302f4---gukegorifeliwobasodoxagaj.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608532636170d---15743482137.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16072355c8296c---84266634767.pdfIn PDF document text
    • http://immobilieninvestors.de/userfiles/file/41472776368.pdfIn PDF document text
    • http://erfaspot.com/resimler/files/benetedavurarimapap.pdfIn PDF document text
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/a5e9mdomnlmcdefiok5c6dgd81/85976233669.pdfIn PDF document text
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609833c67c347---wetenoxejewolupixedatun.pdfIn PDF document text
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/6fbc181126d9865b31b394c7a82d8d29/80045925734.pdfIn PDF document text
    • http://c-amc.com/upload/files/76155409643.pdfIn PDF document text
    • http://residencecarlofelice.com/userfiles/files/wisutibinimunonunoj.pdfIn PDF document text
    • http://hilimall.ae/uploads/files/95719219514.pdfIn PDF document text
    • https://okud-istra.hr/userfiles/file/93693315715.pdfIn PDF document text
    • https://travolution.travel/wp-content/plugins/super-forms/uploads/php/files/896a6098bb113b0a8c38ab48548d5490/sanenunigawavegel.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=2020+cbse+class+10+science+question+paperPDF link annotation
    • 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_off0000e25f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE25F 5424 bytes
SHA-256: 9b912cf0b015f78f17bf387dea34828f2911cdcd88092a911e14b88f53fb2305
font_01_sfnt_off0000f4e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E0 11016 bytes
SHA-256: 526024e5020a2f42bcf4e6b6090b18720b46f4ca6cc96cb46e5d98de58aeacae