Malicious PDF — malware analysis report

Static analysis result for SHA-256 c16f6637c5a32402…

MALICIOUS

PDF

77.2 KB Created: 2021-09-09 10:18:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 7b069df75d4121b8aaaae6f34304cd3a SHA-1: 6839f1428bad531f54ff7fd4a6f34a682f4c26b9 SHA-256: c16f6637c5a32402b984f79cbc19a37d0bbae22c83f669179e827e3c301a9eaa
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised or disposable hosting sites. The presence of numerous unknown URLs suggests an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://0a3exp.com/upfiles/editor/files/wunekerilekavifom.pdf In PDF document text
    • http://www.ferm-matic.fr/upload/file/bemak.pdfIn PDF document text
    • https://everestart.com/images/stories/file/53595791869.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613243fa0f939---91915009179.pdfIn PDF document text
    • https://rajatotogroup4.com/contents/files/xatojusufi.pdfIn PDF document text
    • http://teamwork-poetschke.com/ckfinder/userfiles/files/47057987190.pdfIn PDF document text
    • http://china-engine.net/ckfinder/userfiles/files/niweroborimosafos.pdfIn PDF document text
    • http://wittymall.com/multimedia/userfiles/file/34153658325.pdfIn PDF document text
    • https://branchennachweis.eu/userfiles/file/65413029763.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/atqdq7qa2kb2vuhc98c950ecbn/56264699912.pdfIn PDF document text
    • http://thegioicamdo.com/upload/files/gokadafokalutekobe.pdfIn PDF document text
    • https://bdblue.com/ckfinder/userfiles/files/joxotawixelolobuzefured.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16134819bce96d---10202427763.pdfIn PDF document text
    • http://faisaltowel.com/survey/userfiles/files/gapirijarugabusumetodude.pdfIn PDF document text
    • https://radmangroup-ye.com/rgfiles/file/logezi.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/4912f1a880a71e1e8c4e04077871cefc/6836591491.pdfIn PDF document text
    • https://carcarnet.com/home/sandbox/domains/hkdance.tritek.hk/public_html/ckfinder/userfiles/files/kolalipuxise.pdfIn PDF document text
    • http://vasset.bg/userfiles/file/16072244176.pdfIn PDF document text
    • http://tmkb.org.tr/ckfinder/userfiles/files/49344486146.pdfIn PDF document text
    • http://kpotplace.com/uploads/files/jomegitavezi.pdfIn PDF document text
    • http://autobedrijvenindex.nl/images/uploads/28202177753.pdfIn PDF document text
    • http://distant-property.ru/fck_editor_files/files/88719613593.pdfIn PDF document text
    • https://basundharamart.com/userfiles/file/81102407961.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=storing+music+on+androidPDF 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_off0000cca5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCA5 10708 bytes
SHA-256: 9399f3900e372a775896830ad3134f8bac2cb690ad35ac74279745f451c5b8e4
font_01_sfnt_off0000e4fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4FD 16412 bytes
SHA-256: fe076ea4c84c3e7bb8ab38101e18f37be8a90ca2ba63ef95e61862212354f3cb
font_02_sfnt_off00010f0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F0B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1