Malicious PDF — malware analysis report

Static analysis result for SHA-256 36435b41ab39d9f9…

MALICIOUS

PDF

82.0 KB Created: 2021-10-13 21:57:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: d83fedb13598b81248873c13c315d5b9 SHA-1: 5044050f51508d56d1fa25b1873d5ce1c106bdc1 SHA-256: 36435b41ab39d9f9103a1443693b7b81c88fa729bae86f55560b8dc58b49a85b
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to various domains, some of which are associated with compromised CMS uploads. This suggests the PDF is likely used to redirect users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://harrodsrentacar.com/public_html/userfiles/file/18089218259.pdf In PDF document text
    • http://asja-doll.ru/userfiles/file/posiv.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/74486653507.pdfIn PDF document text
    • https://talenthunt.biz/userfiles/file/58120063994.pdfIn PDF document text
    • https://eclearusa.com/images/file/693138889.pdfIn PDF document text
    • http://canissapiens.com/images/uploads/file/kowov.pdfIn PDF document text
    • http://naturenhuman.com/app/webroot/userfiles/file/jagovomijexinuvibijovu.pdfIn PDF document text
    • https://greenlakepaint.com/ckfinder/userfiles/files/90360003218.pdfIn PDF document text
    • https://aarhuskortet.dk/images/file/16411691889.pdfIn PDF document text
    • https://chulintemple.house-well.com/CKEdit/upload/files/4917585492.pdfIn PDF document text
    • http://sinice-rasy.cz/files/file/liluxijalotutenelisu.pdfIn PDF document text
    • http://zopos.zohukum.com/ckfinder/userfiles/files/93984228296.pdfIn PDF document text
    • http://kibbkw.com/uploads/files/loromanalijebapuv.pdfIn PDF document text
    • https://geniodelweb.com/file/52196795714.pdfIn PDF document text
    • http://banhangcongnghe.com/upload/FCK/file/63309640804.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/161310de57eaa5---88502575866.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2167820a9---rusiwesodujeke.pdfIn PDF document text
    • https://dzido.pl/userfiles/file/fezevakusejemox.pdfIn PDF document text
    • https://centrorevisionimonregalese.it/file/83410256683.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c6faf72bc0---mibupevepetowu.pdfIn PDF document text
    • https://nhatngudongkinh.phapluatvietnam.com/upload/ckupload/files/78022700702.pdfIn PDF document text
    • http://innotack.com/userfiles/file/tuxedafebav.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/5a6ea066ee8604eb807846aae09ed86e/sigexewinavifolixonu.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/u-9XGpgKpwY/uplcv?utm_term=photography+iso+aperture+shutter+speed+pdfPDF 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_off0000d814.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD814 18960 bytes
SHA-256: d13d5c305fb29d3b2117d41dbe21aa2dcb6ec707f548fcc4928d3541abe08389
font_01_sfnt_off00010996.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10996 10840 bytes
SHA-256: 92f9149af8145385e8496ff23190c2f59341162e216c4b2040dcbe5ead35405c
font_02_sfnt_off000122a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1