Malicious PDF — malware analysis report

Static analysis result for SHA-256 a023c619837d0495…

MALICIOUS

PDF

70.6 KB Created: 2021-09-18 23:11:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9d6ceeb5ade2bab4b31ba8c9bfdfbe53 SHA-1: 2c8fd2eb83636b70268668bcf8129a9cc18f0f67 SHA-256: a023c619837d0495eb77ac51ba09fdd38bf4ae074ebb77bcb3a0a46bbe4b3a71
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that function as a link farm, directing users to potentially compromised websites or phishing pages. The heuristic 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' indicates that some links point to compromised WordPress upload storage, suggesting a method for hosting malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://infrive.ru/uplcv?utm_term=how+to+use+phone+as+a+keyboard PDF link annotation
    • http://tecnoservizi.com/userfiles/files/dojibi.pdfIn PDF document text
    • http://sky1981.com/asset/uploads/files/17026648909.pdfIn PDF document text
    • http://fairway.cc/images/blog/file/bilunejowekeviri.pdfIn PDF document text
    • https://orrizon.ru/images/file/gadewovutirege.pdfIn PDF document text
    • http://www.primariasantana.ro/uploads/file/92558054303.pdfIn PDF document text
    • http://theexplorerthai.com/userfiles/files/kurozutunukaxugejekegoku.pdfIn PDF document text
    • http://phelieuviethung.vn/upload/files/43917583756.pdfIn PDF document text
    • http://terezszilvia.com/images/uploaded/file/24410162802.pdfIn PDF document text
    • https://promobryansk.ru/userfiles/files/zajazogik.pdfIn PDF document text
    • https://b7b.reviewz.eu/app/webroot/files/userfiles/files/17979485821.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/945e78ac2345c297a71e38ebc9e2f1b5/79236636221.pdfIn PDF document text
    • http://nsdadventist.org/FCKData/file/82185524737.pdfIn PDF document text
    • https://maftplayer.net/calisma2/files/uploads/rakalijapatuf.pdfIn PDF document text
    • https://ventadeterrenosurbanos.com/userfiles/file/81900357223.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138f1118a2d0---nozelizaj.pdfIn PDF document text
    • http://vhktn.at/images/content/files/60915852139.pdfIn PDF document text
    • http://studiocalcinoni.com/userfiles/files/52855914563.pdfIn PDF document text
    • http://kenzoum.org/home/integrity/public_html/ckfinder/userfiles/files/90073168464.pdfIn PDF document text
    • http://www.adarshvidhyasankul.org/userfilesfile/36900510660.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/53jim0nltovrn57dfuis88t393/26002375592.pdfIn PDF document text
    • http://thueotodn.com/uploads/image/files/mabowogiruzumumu.pdfIn PDF document text
    • http://meandnetworking.com/ckfinder/userfiles/files/jozexigapakesekalizugevop.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/7935870eecf83aeb296fbc815c419dc9/rokevinisure.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_off0000b4e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4E0 15636 bytes
SHA-256: 44925af91e4c2ca79f2c787f53cb74deed200e3cd89bdf40fcf4bd966f105bc5
font_01_sfnt_off0000dc3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC3D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f454.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF454 10876 bytes
SHA-256: 33d50b0200d0146cef507f02eb2cc4f559be6350f24e79c9ea6ec865ee044ed1