Malicious PDF — malware analysis report

Static analysis result for SHA-256 3bb49758a0268634…

MALICIOUS

PDF

69.6 KB Created: 2021-09-23 13:37:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: bc6025a63a236c5be6965493ec3ce9ff SHA-1: 220eebeb2502f97a00e2a1098cf9a59822660648 SHA-256: 3bb49758a0268634487770dbb581123b288da03b947dcf60cbd2218c72b0863e
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as containing a link farm and was identified as malicious by ClamAV and an ML classifier. The document body is heavily obfuscated, but the presence of numerous external URIs, many pointing to compromised CMS uploads or disposable hosting, strongly suggests a phishing or malware distribution attempt. The primary goal appears to be directing users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://medbillings.us/lightspeedweb1/file/kemitesiruvo.pdf In PDF document text
    • http://rc-modeller.se/images/file///kopabipitojep.pdfIn PDF document text
    • http://kronospan-mofa.hu/editor_up/zufiwavirutivodakodixizul.pdfIn PDF document text
    • http://tcsm62.org/uploads/news/file/68070922323.pdfIn PDF document text
    • http://gruppocreta.com/userfiles/files/35733579839.pdfIn PDF document text
    • http://srihemkuntsahibfgp.org/hemkunt/userfiles/file/jogorobet.pdfIn PDF document text
    • https://gogreenonline.net/userfiles/image/fckeditor/file/jawinikoruxirinowaripilu.pdfIn PDF document text
    • http://haciogullari.com/depo/sayfaresim/file/96141368854.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/912e33fb70c1a377e0a5ed7f4c49bae3/vodegenibiripab.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/161494feb06b75---44990395535.pdfIn PDF document text
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/203412e5ba87abef4f3ae8fcc8a00ed1/28023305934.pdfIn PDF document text
    • http://mathrainbow.com/userfiles/file/42859260470.pdfIn PDF document text
    • https://hantverksakuten.se/ckfinder/userfiles/files/28995388679.pdfIn PDF document text
    • http://koreabulk.net/userData/board/file/jizamarudelu.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/u866uoqmse93uc0sku0r9oaoc6/54964913408.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/djnrl83dc2gbkqcpo43iosro87/5062101432.pdfIn PDF document text
    • http://tscyw.net/userfiles/file/20210921075038_m3c5r8.pdfIn PDF document text
    • http://gewald.ru/content/Files/bumopad.pdfIn PDF document text
    • http://duef.ru/public/file/xusipifizoz.pdfIn PDF document text
    • http://ternovykh.ru/content/file/42913680581.pdfIn PDF document text
    • http://misterholidaysanprisco.it/userfiles/files/2941135663.pdfIn PDF document text
    • https://cosmopolitanhotel.eu/uploads/wysiwyg/files/zepoxazakajigi.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614541af614eb---11946352957.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=android+to+ios+transfer+after+setupPDF 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_off0000b31b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB31B 10524 bytes
SHA-256: 8827c2e2df7f81cf1a3aa4f4493cefc9382270c8df9edf8ac9db123a031e93d0
font_01_sfnt_off0000cb30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB30 14768 bytes
SHA-256: 7081b8a0ac80211bf2f66eb5279f4161ebe0001512e296e70f160459d2104549
font_02_sfnt_off0000f07e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF07E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1