Malicious PDF — malware analysis report

Static analysis result for SHA-256 840b0ce21a573947…

MALICIOUS

PDF

75.4 KB Created: 2021-09-26 22:24:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: c6fb081ca84744b05b78249a911fdfb0 SHA-1: 0be3f3c258f9351bfbdc87699169e956bab97dce SHA-256: 840b0ce21a57394702cc55cf34aa3b09bda205a02006fb845376d5b9474116cc
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the extensive use of external links is the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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=redmi+9c+os PDF link annotation
    • http://clearspace-design.com/CKEdit/upload/files/59751353395.pdfIn PDF document text
    • https://machinex-machines.com/UserFiles/File/27202136445.pdfIn PDF document text
    • http://modelseafarm.com/kweb/ckfinder/userfiles/files/58010898436.pdfIn PDF document text
    • https://proartgaleria.hu/files/files/fusiraduvisofevodinasun.pdfIn PDF document text
    • https://it-remarketing.pl/app/webroot/media/files/37415826877.pdfIn PDF document text
    • https://motoquadro.de/userfiles/file/32475857655.pdfIn PDF document text
    • http://relaxzenter.com/uploads/files/jonebovojarorug.pdfIn PDF document text
    • https://vnjhanoi.com/upload/files/lofota.pdfIn PDF document text
    • https://motty-etai-sharon.com/files/files/6759578535.pdfIn PDF document text
    • http://gz-theoutfit.com/UploadFiles/FCKeditor/20210901150333.pdfIn PDF document text
    • http://billagelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vatukozaluledog.pdfIn PDF document text
    • http://sjhtractor.com/d/files/sofamuxat.pdfIn PDF document text
    • http://resortcrimea.com/ckfinder/userfiles/files/99895083333.pdfIn PDF document text
    • https://magicdiscoradio.com/userfiles/file/62880646363.pdfIn PDF document text
    • http://lucidareemantenerepavimentifaidate.it/userfiles/files/bufowurilet.pdfIn PDF document text
    • http://korsorlampang.net/user_img/files/bazukowisorojosobuzarefuv.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16147cca929e99---nukimerub.pdfIn PDF document text
    • https://eletmodguru.hu/files/files/88280149371.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140265f530b9---bemexitem.pdfIn PDF document text
    • http://hunting.kg/userfiles/file/gupamajidawoverurevololek.pdfIn PDF document text
    • http://rongqichem.com/upload/files/3421227550.pdfIn PDF document text
    • http://thebodyclubonline.com/userfiles/file/37580748744.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161453379bffb6---29184808271.pdfIn PDF document text
    • https://laznia-radom.pl/userfiles/file/35913406143.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_off0000bbdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBDD 20204 bytes
SHA-256: 9c74e7fca6c0c3e53231dad9a9c8f984abe732c86af4788e439b6183e512233c
font_01_sfnt_off0000f147.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF147 10232 bytes
SHA-256: 7fbaa347d510dd199158e83ab1116c9a4e33b00220c474a35de47ab9001ee4d7
font_02_sfnt_off00010849.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10849 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1