Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac8f20d8cd1956de…

MALICIOUS

PDF

70.1 KB Created: 2021-09-25 15:47:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0cd3565d77ae870645e5d09c6b1a3d55 SHA-1: d99174b6727a8fc12e18d85e0231f7ea5583957a SHA-256: ac8f20d8cd1956de3397899276c097cb8a0e75820339c24b7e5c5b03ed17d554
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://ooo-kenk.ru/userfiles/file/gazujidopedof.pdf In PDF document text
    • http://bmfjhjk.friend-match.com/upload/files/12664513948.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/t6471a5e5dfl60nlhecv05blnp/vafurojunubiripodu.pdfIn PDF document text
    • http://avvocatoandreabruschi.it/userfiles/files/limatizedixokaregozaj.pdfIn PDF document text
    • http://moveworldtogether.com/datas/files/konaxigofek.pdfIn PDF document text
    • http://celcg.pl/uploaded/file/24663491256.pdfIn PDF document text
    • http://st-ark.it/userfiles/files/49590614489.pdfIn PDF document text
    • http://alpinedelhi.com/userfiles/files/vedafipewomatewepokapok.pdfIn PDF document text
    • http://ipceurope.be/assets/file/rapijoduwafigujimaguvev.pdfIn PDF document text
    • http://ageofwonders.buka.ru/sadm_files/nawagitokapirazoluf.pdfIn PDF document text
    • https://www.ijdsir.com/ckfinder/userfiles/files/gobimanerurusula.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/076fff0fd82b9156983db66665eb5b9a/14001327775.pdfIn PDF document text
    • http://totoquynhhuong.com/upload/files/tuzuvi.pdfIn PDF document text
    • https://performanshost.com/calisma2/files/uploads/11432642751.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614d6bc298514---bujibiv.pdfIn PDF document text
    • http://markjfox.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/98079887356.pdfIn PDF document text
    • https://k-barrierfree.com/FileData/ckfinder/files/20210910_6ECD945F78653356.pdfIn PDF document text
    • http://bonfiremadigan.com/uploads/fckeditor/file/51516191685.pdfIn PDF document text
    • https://martan.es/cenavarra_userfiles/files/giroletut.pdfIn PDF document text
    • http://daiichihr.com/uploads/news_file/7060588737.pdfIn PDF document text
    • https://alnahamgroup.com/userfiles/file/wulugokijeginiz.pdfIn PDF document text
    • http://superfishinglewood.com/uploads/files/44921890995.pdfIn PDF document text
    • https://kamwalibais.com/userfiles/file/durisevalakado.pdfIn PDF document text
    • https://xn--80ag1a2a.xn--p1ai/files/file/galilidajumite.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=watch+seven+deadly+sins+season+4+episode+2PDF 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_off0000b1f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1F5 10880 bytes
SHA-256: c86caca1064f78c416b62b77ad1b121d07e9f462f78a12b7702a6b7777363eb5
font_01_sfnt_off0000cb34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB34 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e346.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE346 15320 bytes
SHA-256: 4742e2a969da82963a944a64ab7328c881086876bae1d8c057e7e56f8869dc4a