Malicious PDF — malware analysis report

Static analysis result for SHA-256 801cfbf9402d46af…

MALICIOUS

PDF

77.5 KB Created: 2021-09-13 06:54:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 1e1ea554f4433a6febeae14c1955e7e5 SHA-1: 04f7b438a2b154916abe29a08d4ce1b162902e77 SHA-256: 801cfbf9402d46aff7471b20b7ce8b625f422d64de07893057c4b4cde6b936bf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for human readability but rather as a container for these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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 http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135211650d9c---1289252153.pdf In PDF document text
    • https://horacebatten.com/ckfinder/userfiles/files/82981185647.pdfIn PDF document text
    • http://yung-shun.com/userfiles/file/rosoba.pdfIn PDF document text
    • http://eternoohydro.com/d/files/65877825928.pdfIn PDF document text
    • http://medizator.ru/ckfinder/userfiles/files/12650208782.pdfIn PDF document text
    • https://homestayhoian.vn/uploads/image/files/givazulobozowuxitil.pdfIn PDF document text
    • http://toyotacri.com/userfiles/files/84364885977.pdfIn PDF document text
    • http://grupopiscis.com/upload/files/zevorudexedozos.pdfIn PDF document text
    • http://kirakuramenandsushi.com/uploads/files/gomuxiveg.pdfIn PDF document text
    • https://oceanflowerhotel.com/uploads/image/files/72918195072.pdfIn PDF document text
    • http://aesg2edcv.handylover.com/upload/files/38220447087.pdfIn PDF document text
    • https://xo-sound.ru/userfiles/file/rewuvizu.pdfIn PDF document text
    • http://ty6600.com/userfiles/file/80922849371.pdfIn PDF document text
    • https://haltia.mx/sii/ckfinder/userfiles/files/93795787484.pdfIn PDF document text
    • http://www.abcklima.hu/data/editorfile/29863374251.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/161307dbb38609---54516655601.pdfIn PDF document text
    • https://cincia.ro/ckfinder/userfiles/files/nunamopemabokakulejunijog.pdfIn PDF document text
    • http://staractivecollection.com/resimler/site/files/kiwuke.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1613e8b8208d5c---zobazudoxobewoli.pdfIn PDF document text
    • https://www.karelo.com/uploads/File/nosarerofig.pdfIn PDF document text
    • http://lutechmed.com/Images_upload/files/lazokilebozo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=mixed+number+equationsPDF 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_off0000c958.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC958 10844 bytes
SHA-256: 9252b22e241eb64f978d1dcfc32c81c6ed95dc0a85eebc5910538cc526952d5b
font_01_sfnt_off0000e22e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE22E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fa40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA40 18052 bytes
SHA-256: 8b3e5bcdcf3d7ed588a7f500f8c1eb65c9a5a8e7232be70634c53419ea9a60fc