Malicious PDF — malware analysis report

Static analysis result for SHA-256 33811d1e5e7946bc…

MALICIOUS

PDF

83.6 KB Created: 2021-09-01 22:10:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9119193ff5d18bdc94178ed2e156f2ef SHA-1: e9756588a5df544176359fec88e276f8107f0712 SHA-256: 33811d1e5e7946bc86748cbf0ab34e7fe9a2e2e4156f65411268ae7075d63b84
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to potentially compromised websites, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the structure itself is designed to lure users to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://efficientinfocomm.com/ckfinder/userfiles/files/36564312000.pdf In PDF document text
    • http://xn----itbbfrdrdbd4bgy6gi.xn--p1ai/webroot/files/files/rapumijenosatenexijifan.pdfIn PDF document text
    • http://ghettaetamionarchitetti.it/userfiles/files/mazinagojepuju.pdfIn PDF document text
    • https://beytarimcilik.com/admin/editor_resim/file/rafabulezuvifatiwagavaman.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1609ade5539b12---zagefinozof.pdfIn PDF document text
    • http://hzdsbg.com/uploadfile/1629393944.pdfIn PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/7ae0267e2557f5ab996d4680ae24e179/35922914526.pdfIn PDF document text
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/qc4lkg7vb7sfsgli6anj2jstt8/fexodasazokonewupi.pdfIn PDF document text
    • http://www.parkwaytransplant.com/media_upload/upload/files/wakimowora.pdfIn PDF document text
    • http://3wsystems.com/shipinc/userfiles/files/kanavokikiliji.pdfIn PDF document text
    • http://lueckerreunion2020.com/clients/e/eb/eba09433058400eda594a485f9004317/File/38698772280.pdfIn PDF document text
    • http://edsmithestate.com/clients/8/8f/8fcea3baa00381bb68ca4dcda22eb4c7/File/sebixivanorizotu.pdfIn PDF document text
    • http://dgjinhak.kr/DATA/upload/files/202106050652183221.pdfIn PDF document text
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/ad0014425e33786b6d194a42120e4a1e/podiwab.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1612a95abab3a6---vetiposirodalunusudiki.pdfIn PDF document text
    • https://akapacha.com/userfiles/file/55295354133.pdfIn PDF document text
    • http://amphorabeautyclub.com/campannas/file/geviloletegojovepawi.pdfIn PDF document text
    • http://fxmeat.com/upload/file/7d6ff9b7c1fbad562248cba2b619ba7d.pdfIn PDF document text
    • http://ipceurope.com/assets/file/8902832849.pdfIn PDF document text
    • https://al-farh-iq.com/upload/userfiles/file/10092186423.pdfIn PDF document text
    • http://gramercygrand.ru/files/file/75613095520.pdfIn PDF document text
    • http://dgxzz.com/uploadfile/file/99537912955.pdfIn PDF document text
    • http://mdfgiare.com/upload/files/72780665510.pdfIn PDF document text
    • http://naphotelbangkok.com/userfiles/files/8550717224.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=jvc+everio+hdd+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://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_off0000e3ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3AB 18584 bytes
SHA-256: ce64c21896f3b50407a54f6be87400fbd355a4d099ccd180162b93d6e6a5cee8
font_01_sfnt_off00011442.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11442 10528 bytes
SHA-256: 80912b72abf8f6b73e6494dd239fad12a36d5950d353ede4cdab5bc786c5df7c
font_02_sfnt_off00012c03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C03 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1