Malicious PDF — malware analysis report

Static analysis result for SHA-256 2a4979b6f70c891b…

MALICIOUS

PDF

93.5 KB Created: 2021-09-21 00:51:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c46b37413b7e0694c7e2f6a1f5ee20c0 SHA-1: 98194e79d0b9d24f19e419ac1341b881d100fd91 SHA-256: 2a4979b6f70c891b95024750888b8f592d300df1dcedbb0cb0d8df8a0a1ef450
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous external URLs were extracted, many pointing to compromised CMS upload storage, suggesting the PDF acts as a lure to download further malicious content or phish credentials. The presence of PDF-specific heuristics like 'PDF_URI' and 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 https://chcial.ru/uplcv?utm_term=copy+pdf+to+excel
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/sg981pulh05p2085n0alfn65a3/47508982339.pdf
    • http://besteva.com/upload/files/42699552824.pdf
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161415e6ab022a---lasusirisosuka.pdf
    • https://restaurant-kamkok.fr/img/Data/file/zererapomomidap.pdf
    • http://bocghebinhduong.com/media/ftp/file/21378304616.pdf
    • http://tangneylaw.com/admin/images/file/puvakazebiniduporumafu.pdf
    • https://digitaluzaktanegitim.com/calisma2/files/uploads/rogovasebefodo.pdf
    • https://ohcsi.com/ckfinder/userfiles/files/11091969177.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16131d85fd40dd---78272513361.pdf
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cadc792b1a---49682225944.pdf
    • https://virker-ikke.dk/files/19940019318.pdf
    • https://cartolmania.it/file/80200765035.pdf
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16132cdb9e4a6c---tebulonuzewu.pdf
    • https://premiersuli.hu/files/files/72085264644.pdf
    • http://morecoredesign.com/images/imageUps/files/poxajisekitinimogufewo.pdf
    • https://mebelihome.ru/upload_picture/nudinokisipodudal.pdf
    • http://matonaklawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/46809970059.pdf
    • http://easternhoteljeju.com/FileData/ckfinder/files/20210919_AC3BDEE18E7ACA79.pdf
    • http://weiddy.com/uploads/files/202109091527145262.pdf
    • http://mpu-beratung-brendle.de/userfiles/file/dabipidanek.pdf
    • http://salsainkonstanz.de/media/files/jared.pdf
    • http://www.shjkyq.com/up_files/FCK/file/rakobukolujimajovotide.pdf
    • http://businessvaluationapp.com/fck_files/file/49774695217.pdf
    • http://wirtrauenuns.ch/images/file/rakotixugesijawaf.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000108cc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x108CC 16792 bytes
font_01_sfnt_off000120de.bin
215a62a0624b18b6ce6087f67e9d529f50cc3b27b98c40380b18b91329a17e06
pdf-font-stream PDF embedded font (sfnt) at offset 0x120DE 18592 bytes
font_02_sfnt_off000150fb.bin
10fdf94c7fded8641d38f5ff6990adf4502c2e6ba14de169127850b3e58c73f3
pdf-font-stream PDF embedded font (sfnt) at offset 0x150FB 10232 bytes