Malicious PDF — malware analysis report

Static analysis result for SHA-256 b933836913296113…

MALICIOUS

PDF

70.4 KB Created: 2021-09-27 04:00:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: c33cbc38e83613dcfdea4723f22e221a SHA-1: 208cba64b1556b2af2c26757575d82e6de4a4eca SHA-256: b933836913296113a98e69f083f89983695a90c2246e5bf9576aeab0113f25d2
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The file's structure and link farm behavior align with techniques used to lure users to malicious sites.

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://crewmak.ru/uplcv?utm_term=world+top+10+gaming+phone+2020 PDF link annotation
    • https://perkunasstudio.com/uploads/files/202109250056013201.pdfIn PDF document text
    • https://rezilta.com/psum/admin/userfiles/file/dujixapadimiluvitopibox.pdfIn PDF document text
    • http://eubeer.vn/uploads/files/22357883980.pdfIn PDF document text
    • https://drhuanghair.com/uploads/files/202109110219346155.pdfIn PDF document text
    • http://bananamusic.tw/uploads/files/202109071918577914.pdfIn PDF document text
    • http://werkkledingverkoop.nl/images/docman/files/94233385036.pdfIn PDF document text
    • http://majedalkarkhi.com/pics/file/modozenesewololatu.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614258d349918---71942361029.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1613a3b213fda1---54878706343.pdfIn PDF document text
    • http://german-ex.com/images/blog/file/6420718724.pdfIn PDF document text
    • http://kaupa.cz/userfiles/file/bufosafezejaboxumoriv.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/4suqlbtkjsnpmgirhb1jq8cfru/besuxunaj.pdfIn PDF document text
    • http://romengo.com/ckfinder/userfiles/files/61939958523.pdfIn PDF document text
    • http://dinobajka.pl/Upload/file/58075566008.pdfIn PDF document text
    • http://sterenstein.ru/userfiles/file/26649798113.pdfIn PDF document text
    • https://korzayithalat.com/spot/admin/fckeditor/userfiles/file/70372657174.pdfIn PDF document text
    • http://richardchong.com/userfiles/files/7437974859.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/7km3cl5bjblglohr1rp3s6it6c/mukumiganisosobofusik.pdfIn PDF document text
    • http://campingwithconvenience.com/files/files/73130826443.pdfIn PDF document text
    • http://ingegneriarossi.it/userfiles/files/18212331582.pdfIn PDF document text
    • http://axi-hohenstein.de/userfiles/file/vibazebepokoraki.pdfIn PDF document text
    • http://evevoyance.fr/adh/.-/file/2296404382.pdfIn PDF document text
    • http://rialta.ie/userfiles/files/gatowenijopixabepa.pdfIn PDF document text
    • https://vargyasnekonyveles.hu/kepek/other/file/surilesekawawenumatuze.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_off0000b2f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2F7 15540 bytes
SHA-256: 0582bfa700dca37153795adf0563d393e70d3338a24b22edce431b7e76976602
font_01_sfnt_off0000da74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA74 10956 bytes
SHA-256: a66d6cd776b6e9706ec1c765c1cf9cbe4dbfd0493e9fc5179936965d1dc47d57
font_02_sfnt_off0000f378.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF378 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1