Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5841c79af8c7b94…

MALICIOUS

PDF

69.8 KB Created: 2021-09-12 02:31:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8157ee4e7c26360a690d030ced1a2c7f SHA-1: 744e819be1e07543cf8b444072c2c75e7a948ebd SHA-256: f5841c79af8c7b9427ba5ea33b0e2cb20b0b8978c3030687e2f4dd5a57582069
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 directories, forming a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery through these links. The presence of multiple PDF link farm heuristics further supports this conclusion.

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 http://cisseo.net/userfiles/files/robukukugaxojametesomif.pdf In PDF document text
    • http://grasslandtj.com/upload/files/tesuxaworaxegezaduvij.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613d1c9f9ede3---44767076721.pdfIn PDF document text
    • http://xn--80aafjbaeihgganggf9ajkncugh2a.xn--p1ai/pict/file/razatemo.pdfIn PDF document text
    • https://mytekas.com/UserFiles/file/94305311391.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/gunojoso.pdfIn PDF document text
    • http://dragonera.cn/admin/userfiles/file/xudedaz.pdfIn PDF document text
    • https://pima-alarms.eu/slicice/file/80780958894.pdfIn PDF document text
    • https://pt2-turbo-j3t.com/contents/files/potefomilakeses.pdfIn PDF document text
    • http://royalleasingny.com/admin/images/file/konuwesumuvulir.pdfIn PDF document text
    • http://allycatering.com/userfiles/59481418331.pdfIn PDF document text
    • http://parejalecaros.com/adjunto/upload/fck/files/20205433959.pdfIn PDF document text
    • https://trungtammatnamviet.vn/upload/files/pifirofilebezor.pdfIn PDF document text
    • https://manenshop.com/upload/files/10184719699.pdfIn PDF document text
    • https://tideandtigers.com/ckfinder/userfiles/files/67976346071.pdfIn PDF document text
    • https://wrd13.com/force/file/kifofuxipudetuvatolefegiz.pdfIn PDF document text
    • https://alummaswaja.com/yii/sdbalikpapan/home/images/upload/files/zoxuwevim.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613d36235f84b---bozikasogesuzejekajat.pdfIn PDF document text
    • http://greensquares.in/userfiles/file///fadexiwuw.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/161365b9d3d2c3---34915733540.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=how+to+make+an+app+not+use+internetPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b0df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0DF 15924 bytes
SHA-256: 6feca6ac2c362aa6a9a3cb35bf7bb6fe6b12e50042054e44f2178694021a598d
font_01_sfnt_off0000d983.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD983 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f19a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF19A 10636 bytes
SHA-256: fb18c0fd3f8ac310a158ce37258c214317400f1c1ffd7cd7a26b278a9aec35aa