Malicious PDF — malware analysis report

Static analysis result for SHA-256 f21d8ae615ae1279…

MALICIOUS

PDF

84.6 KB Created: 2021-09-03 21:52:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1a19c00d3931495d084ba74f8fd984b1 SHA-1: c2f053a6df315530097c2ae0dc7956557aa5984c SHA-256: f21d8ae615ae12799c09022c000a6e240a795c74224c7c189d7f42e48b1fc4b1
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to various websites. Several heuristics indicate that these links are hosted on compromised CMS uploads or disposable hosting, suggesting a tactic to obscure malicious activity or manipulate search engine results. The primary purpose appears to be directing users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://dongkoo.com/uploads/editor/files/dumidaxonefinofapikupirij.pdf In PDF document text
    • http://antoniolescio.net/userfiles/files/boloduv.pdfIn PDF document text
    • http://stensoproject.com/userfiles/files/gafifaritaxewazidava.pdfIn PDF document text
    • https://cvsc.co/userfiles/file/rorunugidolajawokoxevote.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160b4978059d97---kufufekewe.pdfIn PDF document text
    • http://pwr-tech.ru/userfiles/file/fobizuruponanuborimudiweb.pdfIn PDF document text
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/f10cbddba4b7f9e81c61f26e3eaceecd/dekefozanumipenagezodore.pdfIn PDF document text
    • https://detector-billetes.com/Imagenes/file/juloketozas.pdfIn PDF document text
    • http://matstravel.ru/userfiles/file/sapazuzesitazus.pdfIn PDF document text
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/65e714abd531f7c9c2aa735390586537/99659360701.pdfIn PDF document text
    • http://maynenkhiinverter.com/media/ftp/file/nezegisopa.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/febitetobamiti.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/18261452676.pdfIn PDF document text
    • https://people11people.com/uploads/File/4417379402.pdfIn PDF document text
    • http://atenngo.com/admin/sites/site/documents/rofigi.pdfIn PDF document text
    • https://elnativocoffee.com/silver/upload/files/netoxedivibodat.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1607735e7dd236---36082926840.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/16077fdea1d681---51371591272.pdfIn PDF document text
    • http://outspokenholland.com/userfiles/fckFile/20210826041107.pdfIn PDF document text
    • https://mobistore.co.nz/wp-content/plugins/super-forms/uploads/php/files/7b98cd4142d9ebb0acfe95eacfddeb94/jerisinajimozikilobudox.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa35621ca96---90015615187.pdfIn PDF document text
    • https://valdisieveshopping.it/file/wowakeduguloxu.pdfIn PDF document text
    • https://ivaco.it/file/sufasinipusenev.pdfIn PDF document text
    • https://broadcasthub.com/ci/userfiles/files/dunuwoxawotuluvixafosaw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=laserjet+pro+m102w+user+manualPDF 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_off0000e53e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE53E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fd50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD50 17852 bytes
SHA-256: 56af48f2d2478fc8c5c1fe0b6fe5182b1c51cc84ea8d33271ad60272b0550efa
font_02_sfnt_off00012b6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B6E 10888 bytes
SHA-256: d7c482a97f5fd3eff7526d3674b685f64fe134ae4eb4e4dd7f25b48f26746332