Malicious PDF — malware analysis report

Static analysis result for SHA-256 4dcaba5844155642…

MALICIOUS

PDF

76.9 KB Created: 2021-08-07 19:54:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 0fddbb9e5c3067329355e291106c4501 SHA-1: 2dafcf73298f1f58a96697fcf70d9029db51ca85 SHA-256: 4dcaba584415564280f8e5c29252b6fbc54494ff2da52f51b612e9b1ec2f61b9
156 Risk Score

Malware Insights

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

The PDF was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains a link farm pointing to multiple compromised WordPress sites, suggesting an attempt to lure users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607bccc8d2189---tapimosusosakujasifaroxa.pdf In PDF document text
    • http://holidayinntorino.com/userfiles/files/67085218129.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f138560a4f---rajefakip.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/200ab6826c4acde16d08f7acd6aa0be8/zojuwukarebafobenajakig.pdfIn PDF document text
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/5iulk6dcj8nq2ml1i01bbmgnk2/22054266892.pdfIn PDF document text
    • http://z-i-f.ru/userfiles/file/78599519396.pdfIn PDF document text
    • http://china-miyaco.com/img/file/2021710145946.pdfIn PDF document text
    • https://rhodium.vn/uploads/news_file/vadonisawujum.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/9165966d3ebbe9b59316a4a7bc081b83/15210517442.pdfIn PDF document text
    • https://labelmarket.pl/data/file/46073241976.pdfIn PDF document text
    • http://autoscuolemontagna.it/userfiles/files/gekupopusaw.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/bn4iueohqknc1om6p85c357rd5/lofofetus.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1608067a39efcd---43807581666.pdfIn PDF document text
    • http://lica-mpt.it/userfiles/files/lexerigogawadudotapodukul.pdfIn PDF document text
    • http://simonide.org/userfiles/file/98995708039.pdfIn PDF document text
    • http://mlead.net/images/e/file/zezexisamani.pdfIn PDF document text
    • http://vaness-sens.fr/ckfinder/userfiles/files/tilukijedilizo.pdfIn PDF document text
    • http://yournamebadges.com/withyourdog/cms_uploads/file/valulegopelimukemibed.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9cdd0712ca---gikebajajewimaneko.pdfIn PDF document text
    • https://simondaulte.com/ckfinder/userfiles/files/2744861477.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/bn9goi9hb8ll384hjj99r16pm0/40012623312.pdfIn PDF document text
    • http://leadershipcareer.kr/fckeditor/_upload/file/61246087626.pdfIn PDF document text
    • http://lempreintedubois.fr/userfiles/lempreintedubois.fr/file/70386254918.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=stihl+bg55+owners+manualPDF 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_off0000c8a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e0bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0BF 11088 bytes
SHA-256: deddbf2614899c5d9dca9cb5a4b5f3c0167ecf8b261ceb4bd17edbf228dde729
font_02_sfnt_off0000fa76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA76 16540 bytes
SHA-256: 9d5da0dc26a135a3fc74c0c8206ac3e0649f59ed8652a448eb449dd943e9c6f1