Malicious PDF — malware analysis report

Static analysis result for SHA-256 bacb58671845d555…

MALICIOUS

PDF

73.5 KB Created: 2021-09-09 18:44:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ebb867dddc08bdf4dacf0bcb23ba0732 SHA-1: 7b0becdc599104689d59cfba6909d3702747dc58 SHA-256: bacb58671845d55568d63d821844f2deaeccd23f2073df2572a8bc7cdc7b4b84
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Numerous external URLs were extracted, many pointing to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports the conclusion that this document is a lure for external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://crewmak.ru/uplcv?utm_term=remote+ac+sharp+di+android PDF link annotation
    • http://mezon.jp/userfiles/file/jagafolebesewojumatapis.pdfIn PDF document text
    • https://billionbosses.com/ckfinder/userfiles/files/497589272.pdfIn PDF document text
    • https://jsptti.com/ckeditor/ckfinder/userfiles/files/55373974901.pdfIn PDF document text
    • https://alternativecarrepair.nl/userfiles/file/43924151348.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/18f511d1a4a1e5bf42153c6261252483/tulajatimelabodipojenobot.pdfIn PDF document text
    • http://budoprojekt.eu/obrazy/file/wupafokox.pdfIn PDF document text
    • http://cmtoolsrental.com/user_img/files/23263388598.pdfIn PDF document text
    • http://pravkniga.ru/files/userfiles/files/58979204111.pdfIn PDF document text
    • https://ewt.cz/res/file/26095266856.pdfIn PDF document text
    • http://donghotam.com/luutru/files/soxupojozi.pdfIn PDF document text
    • http://cdwy028.com/uploadfile/file/20210902015209.pdfIn PDF document text
    • http://thaimassageboy.com/ckfinder/userfiles/files/nutuf.pdfIn PDF document text
    • https://koratspring.com/upload/file/sadawilukoriregetoxe.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16139e2b4d8e91---1334049140.pdfIn PDF document text
    • http://gyogytornasziget.hu/uploads/files/xisapefabezesajegejigo.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/xozudolizexekupumaro.pdfIn PDF document text
    • https://landtop.com/filespath/files/20210907154959.pdfIn PDF document text
    • https://ultralloy.net/upload/files/36390377980.pdfIn PDF document text
    • http://vicc.huh.hu/UserFiles/File/dejuwibujek.pdfIn PDF document text
    • https://ikuseikyokai.jp/ckmedia/files/55290062034.pdfIn PDF document text
    • http://synhbio.com/upload/files/68476225776.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612fd981061dd---newemo.pdfIn PDF document text
    • 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_off0000bdc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDC0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d5d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5D2 16392 bytes
SHA-256: 6e109a92d0af4f5398165227aa203de99d3dc4e2d8dfa54efe113a943d9565b1
font_02_sfnt_off0001000e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1000E 10780 bytes
SHA-256: 90795e4a72cc2eaebd8e7d8f4b5f76d0811b2e690c2c2ce97053ee4d201da73c