Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6c27f5517633a36…

MALICIOUS

PDF

87.6 KB Created: 2021-07-30 17:06:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: d1accc59ad0b8443f4b132b2e46c7afd SHA-1: 6f2e02e710887a8885b7a0f4208ab65cb2c111cf SHA-256: c6c27f5517633a369dfc8dc06bb1b09035f03871305fdc156d83ae1268bc4466
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam. The presence of external URIs and link farm heuristics points towards a malicious link distribution pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://chcial.ru/uplcv?utm_term=how+to+build+a+simple+bunk+bed+ladder PDF link annotation
    • https://termofriz.rs//files/72578276112.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073209f18298---kugidenar.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/71bed565a2d7adb61d99eb05d9e00839/60718340858.pdfIn PDF document text
    • https://vildmarksjagt.dk/userfiles/file/80129730931.pdfIn PDF document text
    • http://obasekiestates.com/UserFiles/file/vekijiremanuzarixi.pdfIn PDF document text
    • http://luvnchrlysenglishtoys.com/clients/861429/File/beruwewurizozutesekitasu.pdfIn PDF document text
    • https://diarch.in/WYSIWYGImage/file/ravuzivezekaboduveg.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/12blgiajj9tit7qlind9lnu3if/siton.pdfIn PDF document text
    • https://ccveg.org/wp-content/plugins/super-forms/uploads/php/files/3loiopljt7q20gmpeh78i0glgu/15398025912.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/a05a54aefdb4b38e0bb75f1c3e1dc7ed/76736372995.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608afb898e711---48250055607.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1608db099c27a1---najekajex.pdfIn PDF document text
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/2fe0f0d795f0d27518da372021e2b2f1/puxigonenanuvemodixijo.pdfIn PDF document text
    • http://nw-line.ru/generic/uploaded/80959016629.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/kawesixo.pdfIn PDF document text
    • https://study-abroad-travel.com/ckfinder/userfiles/file/gupapuxutawixupanesexigi.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160739dea95fa3---72160220345.pdfIn PDF document text
    • http://datavincity.com/uploads/ckfinder/files/12993258796.pdfIn PDF document text
    • http://ipmarketing.net/userfiles/file/63560976656.pdfIn PDF document text
    • http://doktor-okonski.pl/uploadimg/file/poteka.pdfIn PDF document text
    • http://nage-z.com/ckfinder/userfiles/files/kiwarewenivokamabalanip.pdfIn PDF document text
    • https://matfreklam.com/calisma2/files/uploads/99749861855.pdfIn PDF document text
    • 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_off0000f1f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010a03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A03 17240 bytes
SHA-256: a4997f6c4dc0b8152e51df295528192e89de25925858f4a0e69ab8cb79e8ef57
font_02_sfnt_off00013761.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13761 10960 bytes
SHA-256: 0f0f58aa4ae5d251c56beb0abe92349025a84a1268e1f7d6a936b5b2bf09d203