Malicious PDF — malware analysis report

Static analysis result for SHA-256 4da4a7df091ed8b2…

MALICIOUS

PDF

82.7 KB Created: 2021-09-10 16:37:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 42dc4131df6f403bb0c3f874788c65ac SHA-1: 9e89c5194b52816a76c222b97397bfd8c326c3af SHA-256: 4da4a7df091ed8b2e89f80622e5db6effbac2d5594f3751ed4118eb6e4434943
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. It contains a link farm with numerous URLs pointing to disposable hosting and compromised CMS upload storage, suggesting an attempt to distribute malicious content or phish users. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the presence of these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://sinching.com/uploadpic/files/202109030309584114.pdf In PDF document text
    • http://simp-q.ru/userfiles/file/17083896940.pdfIn PDF document text
    • https://gres-k.cat/userfiles/file/71518463004.pdfIn PDF document text
    • https://www.southdownscellars.co.uk/ckfinder/userfiles/files/50930633231.pdfIn PDF document text
    • http://web5gstore.com/Files/files/kadabekukorifijowom.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/e902a30c4a38b3d3171c93dfca6ba68a/67337460153.pdfIn PDF document text
    • https://cbdc.co/uploads/ckfinder/userfiles/files/59246351180.pdfIn PDF document text
    • http://3colorjazz.com/fckeditor/userfiles/image/fularub.pdfIn PDF document text
    • http://ytlcases.com/userfiles/file/zavesigedowazuzaxunuv.pdfIn PDF document text
    • http://zhymwz.com/upfile/file/lejijugupewokogilapeb.pdfIn PDF document text
    • https://banderlogclub.ru/Files/file/31002596478.pdfIn PDF document text
    • http://abwclayton.com/uploads/files/42915751535.pdfIn PDF document text
    • http://stavebnevyrobky.sk/www/upload/files/60768636450.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613763a495920---jukoxaj.pdfIn PDF document text
    • http://lmnn.ru/userfiles/file/18017959173.pdfIn PDF document text
    • http://jeyadhurgatemple.com/userfiles/file/75017480790.pdfIn PDF document text
    • http://dieta-plus.pl/userfiles/file/89400568516.pdfIn PDF document text
    • https://jewfri.kr/files/image/files/pevavomo.pdfIn PDF document text
    • https://terlickodds.cz/www/www/fckphotos/file/bepuxakewowekew.pdfIn PDF document text
    • https://nasco-ye.com/uploads/file/84812290848.pdfIn PDF document text
    • http://gewoongroen.eu/app/webroot/files/userfiles/files/6094865442.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee1abc6a59---18194761688.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=any+good+android+gamesPDF 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_off0000def3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEF3 17848 bytes
SHA-256: bf235039b9b738e45b20c7be2480b589d67da97aaba0b720a74b0d3eb889158e
font_01_sfnt_off00010d44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D44 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001255b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1255B 10544 bytes
SHA-256: cd1e037ff2ab281b20a8201a726e8ceb11e08dfcc94eb184ac134173bbacc310