Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6bfda9b792d2772…

MALICIOUS

PDF

81.5 KB Created: 2021-09-20 23:52:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 39da07a116174be563be815c30cda0b5 SHA-1: 73b40e4cfaf5f4f4557770e793c35ace8e573a76 SHA-256: c6bfda9b792d2772afb0f7ccd227fa6abc6e29ce44b26c637b07add2e57b5b18
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users to malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. No scripts were extracted, and the document body was unreadable binary data.

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://viethanit.vn/hinhanh/file/47731246551.pdf In PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/161464efde594c---24193445042.pdfIn PDF document text
    • http://jcbcharpentebois.com/ressource/site-image/files/sominifopadunidaduva.pdfIn PDF document text
    • http://www.gitialiganjlko.org/ckfinder/userfiles/files/9260863918.pdfIn PDF document text
    • http://www.leposeur.fr/site/upload/ckfinder/files/nawonesekokijuf.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/161388283a11c5---pedur.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613163bb18623---881447662.pdfIn PDF document text
    • https://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/gupoponitavugakopaxid.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/94625914705.pdfIn PDF document text
    • https://cakkue.com/contents/files/81126930209.pdfIn PDF document text
    • http://bckbytow.naszbip.pl/img/upload/files/1169841995.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/9592699128.pdfIn PDF document text
    • http://aftckwt.com/uploads/file/padoxadigizurawutikasik.pdfIn PDF document text
    • https://mosconi.net/userfiles/file/manulipudolagujudipuvetuk.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/161415c97ac8e9---kawizaj.pdfIn PDF document text
    • https://wildarium.com/ckfinder/userfiles/files/54272436193.pdfIn PDF document text
    • https://greenlandpark.com/uploads/files/rijodebidekibuvufivo.pdfIn PDF document text
    • https://nieruchomosciprzetargi.pl/files/file/xafidipebifinino.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb9cee0195---38426155632.pdfIn PDF document text
    • http://babyindex.nl/images/uploads/wusutugotodenazanovozos.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/161417cedac27a---ganise.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/59064602197.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16136dc1b42706---57823528635.pdfIn PDF document text
    • https://stgeorgedentalcare.in/ckfinder/userfiles/files/movajapufexogipixalalexe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=android+get+location+managerPDF 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_off0000d712.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD712 10524 bytes
SHA-256: cdbcdc8d39e0c5fe585af577f114f7147aadee032245da9cd5a73b762966fe94
font_01_sfnt_off0000eecc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEECC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000106de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106DE 19172 bytes
SHA-256: 4f2d045b8e3e9703e709f5b62f1955de20fb296d779e893dd26f401d2d72f146