Malicious PDF — malware analysis report

Static analysis result for SHA-256 91b6da4824d128d4…

MALICIOUS

PDF

87.3 KB Created: 2021-09-08 18:04:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 84d464be0143d45ff734a3773ff39b0a SHA-1: a712e98485e3cfee368013c04a33c8a2ae6b7132 SHA-256: 91b6da4824d128d4bdd0775770fbf2606d59a0c0996364e411231dec70b405a6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload storage, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9731

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://www.hotel-restaurant-plainfaing.fr/ckfinder/userfiles/files/48368217458.pdf In PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/8a38a4fee3e4459cd1db454cd3602b07/64328528158.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613036cde659e---lufuge.pdfIn PDF document text
    • https://bda.ch/ckfinder/userfiles/files/jepebisemulav.pdfIn PDF document text
    • http://datcat.vn/2018/file/24185721444.pdfIn PDF document text
    • https://cambodiaangkorhomestay.com/userfiles/file/23983877174.pdfIn PDF document text
    • https://benmoonpharma.com/userfiles/file/36111214236.pdfIn PDF document text
    • https://bhsbeacon.com/FCKeditor/file/79922963021.pdfIn PDF document text
    • http://www.fashiongale.ro/userfiles/files/34564710393.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/90572714797.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/butok.pdfIn PDF document text
    • http://vitanova-cattery.com/upload/file/11080268549.pdfIn PDF document text
    • https://ud-hobby.com/images/Upload/file/10391300633.pdfIn PDF document text
    • http://dj-maily.com/uploads/pages/files/91956145028.pdfIn PDF document text
    • https://al-farh-iq.com/upload/userfiles/file/63241973761.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/de51c4a7d5fa34a1e2deb11a03282c4b/56686263278.pdfIn PDF document text
    • https://ou-ravda.com/ckfinder/userfiles/files/43781431168.pdfIn PDF document text
    • http://graviroz.hu/ckfinder/userfiles/files/munenu.pdfIn PDF document text
    • https://darshanam.com/ckfinder/userfiles/files/donakowetogevinazovus.pdfIn PDF document text
    • https://brtim.com/uploads/wysiwyg/files/783681269.pdfIn PDF document text
    • http://entryexpress.online/chapter_images/files/99089496667.pdfIn PDF document text
    • https://playerpress.com/ckfinder/userfiles/files/47777270975.pdfIn PDF document text
    • http://uralinteh.com/uploads/files/69298998335.pdfIn PDF document text
    • https://el-tall.pl/pics/file/95159634942.pdfIn PDF document text
    • http://thietbidienmpe.net/upload/files/tesabu.pdfIn PDF document text
    • http://minhnguyenvn.com/uploads/userfiles/file/2849716688.pdfIn PDF document text
    • http://caramelitos.sk/files/wuporevuxiser.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=manual+feed+load+paper+error+brotherPDF 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_005_off000117bb.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x117BB 18968 bytes
SHA-256: c98c03e1bbe29e484b2d638aa086020f6dd00a29ea2a66024b4399794f812359
font_00_sfnt_off0000d29c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD29C 17812 bytes
SHA-256: 6974448e8479405f175b84b571ba70a9363ef74987214133444225b0da8f5556
font_01_sfnt_off0000ffaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFAA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off000136c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136C1 10568 bytes
SHA-256: 2a82b92182e0e50c8023aece0841eabdf9b401595edddb03a5fae045536bfd51