Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5cca53fbbdf7c5c…

MALICIOUS

PDF

74.0 KB Created: 2021-09-14 09:38:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4e7b6ef2a0ed7aefbc1825ba71a8f269 SHA-1: 98aa4b540b7c7188ad6d3733983a12f9e2bdd384 SHA-256: a5cca53fbbdf7c5c0e16ef599b43e9463388b386a5ffa91cb50e3a194d596dd6
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, and the document body was unreadable, so the rationale is based on the URL heuristics and AV detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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 http://tianfonmm.com/d/files/95958320770.pdf In PDF document text
    • https://comobrew.com/newsite/images/user_uploads/file/17562733043.pdfIn PDF document text
    • https://optimumquestsolutions.com/ckfinder/userfiles/files/81161848689.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613758558d27b---80185737429.pdfIn PDF document text
    • https://rpdev.org/ckfinder/userfiles/files/madiporipanota.pdfIn PDF document text
    • https://produktybhp.pl/pliki_user/File/5712680583.pdfIn PDF document text
    • http://wamaeassociates.com/images/uploads/originals/file/babifomaforofilumivota.pdfIn PDF document text
    • http://duocthientam.com/uploads/ckfinder/files/nepuwedegajojoz.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/b1e7sep68k3ehv9a2j3g4cdsmf/gakewod.pdfIn PDF document text
    • https://webmenuplus.com/images/file/65176660595.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/fumuzatowisusomebitubuxek.pdfIn PDF document text
    • https://saigonservices.vn/images/uploads/files/kodotuwomimevipaxizebomup.pdfIn PDF document text
    • https://cv-vezouze.fr/media/file/negenixowix.pdfIn PDF document text
    • http://i-harmonics.com/upload/files/23369411802.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ae134ef111---fomiviveramogofa.pdfIn PDF document text
    • https://mut-zur-veraenderung-hambuch.de/userfiles/file/kilurarogu.pdfIn PDF document text
    • https://gentrilieu.vn/userfiles/file/9515040405.pdfIn PDF document text
    • http://stamforgtechnologies.com/uploads/potomodul.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/d1cb159e13f336658f7980d69a5cb8a8/18116104080.pdfIn PDF document text
    • http://vongtaygiay.net/media/ftp/file/bijodisufulo.pdfIn PDF document text
    • https://reha.bg/content/upload/file/61702212981.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/54li1u91a0sjuvmami3l460kca/12912792808.pdfIn PDF document text
    • http://hzdsbg.cn/uploadfile/1630783671.pdfIn PDF document text
    • http://eubeer.vn/uploads/files/jenaromituwejizixovejugu.pdfIn PDF document text
    • http://wintec-samu.hu/uploads/files/sefazevebabojabofifaso.pdfIn PDF document text
    • http://uniondrygoods.com/fckeditor/userfiles/file/rorabide.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=amazing+spiderman+2+apk+modPDF 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_off0000bfef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFEF 10844 bytes
SHA-256: 0ba6bf5f28e81ca1661320fe0034f168207b4c6fe35b0bada27f9b795a0d4a06
font_01_sfnt_off0000d8d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8D2 16324 bytes
SHA-256: 908ce643bb49b1785406897db3c7403f32c88e0307c5f2b042f66560c87bd5aa
font_02_sfnt_off00010218.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10218 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1