Malicious PDF — malware analysis report

Static analysis result for SHA-256 6739cdb875846db0…

MALICIOUS

PDF

83.7 KB Created: 2021-06-25 12:59:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 688c257697d43bbe6524b72458558ed8 SHA-1: 43ec9efc9f0a36923ac689c77bf2ce6f241f7720 SHA-256: 6739cdb875846db0a6f5189bbe3bc5aab400299f1ae039ec03d9a52125bd67b1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external URIs and is identified as a link farm pointing to compromised WordPress upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the structure and URL patterns suggest it's designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://wastran.ru/uplcv?utm_term=another+name+for+cortisone PDF link annotation
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071f945b4950---97003511806.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/19d9ae4ed94c59c646a0910d6bac233c/62032928803.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16071747ba9a77---lokelupadim.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-5-6/20210506070354410620.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/9c90f6131c601d08222ac52ef99c9f93/remavopekipapaxiburupojur.pdfIn PDF document text
    • http://hosungtour.com/FileData/ckfinder/files/20210526_0EA6E0DB82D1FB55.pdfIn PDF document text
    • https://emmaushuis.org/pages/77878117435.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1a27691b53---timijigenoxajede.pdfIn PDF document text
    • http://wksystems.net/HotelEstimator/userfiles/file/87626505928.pdfIn PDF document text
    • https://damiel.eu/userfiles/file/68150806377.pdfIn PDF document text
    • http://malagi.pl/user-files/fck/file/wigipefifox.pdfIn PDF document text
    • http://nutricion-intravenosa.com/wp-content/plugins/super-forms/uploads/php/files/ce5920036c169d0a86edeffe0be3b824/lonemofanedofo.pdfIn PDF document text
    • http://hzjksj.com/images/upload/File/zititisesevimirivufar.pdfIn PDF document text
    • http://nowyhotelik.pl/userfiles/file/rapivavuredis.pdfIn PDF document text
    • https://taichielite.com/louis/taichi/ckfinder/userfiles/files/97998637671.pdfIn PDF document text
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/5v0cr34572jp9lpo64on0nruq2/61195691149.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a09f40a31a4---xikebuvabejexesix.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_off0000e631.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE631 10536 bytes
SHA-256: 38ec9433fd3360669316a63224eeec7c808054789697f66cc3b9905e3d8d53f0
font_01_sfnt_off0000fe0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE0D 16792 bytes
SHA-256: 24714f9bb664d818e80895ef86dec7aabf0568091d31804856d6511dc2cbc371
font_02_sfnt_off000129e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129E3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1