Malicious PDF — malware analysis report

Static analysis result for SHA-256 7855bf1df94a590b…

MALICIOUS

PDF

82.3 KB Created: 2021-08-25 03:44:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 12c80855d4cc3e01b5c104d19fb0211d SHA-1: ececa5634bd91a416bf354b99c15066dbb58bac5 SHA-256: 7855bf1df94a590bb3785f1216289f5b24126cd1170b27cf8343a68a7a291d66
156 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various websites, many of which appear to be compromised CMS uploads. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a non-clustered link farm on disposable hosting, suggesting an attempt to distribute malicious content or phish users. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://smidgel.ru/uplcv?utm_term=mixed+occupancy+building PDF link annotation
    • https://nguyenthelong.net/userfiles/files/gimavajanomutorixejizud.pdfIn PDF document text
    • https://dtcprojects.com.au/wp-content/plugins/super-forms/uploads/php/files/59hn1tl48ro2fhkiks5ppi1olc/sarulogawewalumepu.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/929778c1d021aadc91ff28216d192cdc/mojalidilaki.pdfIn PDF document text
    • https://sip7.pl/autoinstalator/sip7.online/wp-content/plugins/super-forms/uploads/php/files/a8423cfd8119caee32eed7616f4ad93d/bozavaxejaxirubifil.pdfIn PDF document text
    • https://sandzak.best/wp-content/plugins/super-forms/uploads/php/files/2e779f016a2d7172c8860130c2053074/47094984178.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa66cb8f5f---6339304728.pdfIn PDF document text
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e5d7e16d4f---90580770548.pdfIn PDF document text
    • http://csc-020.com/userfiles/file/20210626143430_0ditra.pdfIn PDF document text
    • http://littlepearlbooks.in/data/eimages/file/15034945353.pdfIn PDF document text
    • http://staceyasp.com/UserFiles/file/26704076067.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/d43f7d57fffda0349ebb630e9cba7a22/79948188867.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160853fed6818b---6962239136.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/f179317769ca279967cdd5afd226cc70/41721677129.pdfIn PDF document text
    • http://megat.pl/uploaded/fck_files/file/jijuxazufi.pdfIn PDF document text
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/6b66772ff02532a939be5306c739d2fd/65281149757.pdfIn PDF document text
    • https://altonika.pro/files/fck/file/juwatabedix.pdfIn PDF document text
    • http://designerhouse.ru/upload/files/1985762067.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609832d111829---35010556451.pdfIn PDF document text
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/3cee504b504c38acd22d1526777880e5/sobafezifeta.pdfIn PDF document text
    • http://aodaiminhhanh.com/app/webroot/uploads/files/38437233526.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_off0000dd4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f55e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF55E 17536 bytes
SHA-256: 80bff5defeec9b9f830c8e38cc69ec6e11d6dbea16f1e636aea6b11a39674a49
font_02_sfnt_off00012328.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12328 10772 bytes
SHA-256: 89ca06997fe412ddbd93d0219ec1276b14306f35c548f90faf7f492e58e9a589