Malicious PDF — malware analysis report

Static analysis result for SHA-256 7cdf03852bf23b55…

MALICIOUS

PDF

95.1 KB Created: 2021-06-25 14:12:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 1d35b9e6a72675083f1e2de3bd1949d5 SHA-1: 2d0f73919a75ea02055e606c6857fc794786fbeb SHA-256: 7cdf03852bf23b55f3f57c4c127d6af188986d7ae6fa86c00720ae22f8ca4804
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF contains numerous links, many of which point to compromised WordPress sites, suggesting a phishing or malicious redirection scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious content or downloads. The document body is heavily obfuscated and unreadable, providing no direct textual clues to its purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/03126d146bdfcf2cd5589be0de1e4b5e/mubadawamuresajites.pdf In PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/65168a1ff000e179c5c13973dcfe87cd/24148876662.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/32680551193a1ed694b4ae59e8cffa46/zibituleferubebap.pdfIn PDF document text
    • https://mimpiindah1.com/contents//files/luravexux.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/66pui8i5jk657i38lguv1hvm6n/nasanozu.pdfIn PDF document text
    • http://opalsolar.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608720ac876aa---sebemuferowojuri.pdfIn PDF document text
    • http://forspeed.cz/ckfinder/userfiles/files/liguromadubonamejijiz.pdfIn PDF document text
    • http://casier-a-bouteilles.fr/file/kiwuletorusokutagivugunal.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc821979d68---52403182101.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b882149102b---fememumuvolagodukiva.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/16096793788387---lobelazowelipevapefisanon.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095b88108a43---wakokilokakuluzoruf.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608bac71a57af---riwewimome.pdfIn PDF document text
    • http://sskj.pl/userfiles/file/19407655739.pdfIn PDF document text
    • https://isabellepieman.com/userfiles/file/nukitaguvodifojejazax.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=hollow+cheeks+meaningPDF 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_off00010a60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A60 19824 bytes
SHA-256: fbaeedf5dd7f0bb8de167ea0c2340c62a7a4c007377d1a7551e2d9233cf4ff5b
font_01_sfnt_off00013e1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015633.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15633 10648 bytes
SHA-256: 5b07ae3a0a437743b6b3e015a91411446c37e317d17dd3f6cfd0efdcda57e7cd