Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a5cdbc52414c32b…

MALICIOUS

PDF

81.5 KB Created: 2021-09-20 01:11:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 98e9d52aaa2a67a0063441ad8e861c8b SHA-1: de68078555dfa27a6c47edffa8156afe2c14cc46 SHA-256: 5a5cdbc52414c32bfe5a39f2be7decc590d1be37ce3e8286425f40683be881e1
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 CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://crewmak.ru/uplcv?utm_term=structural+and+functional+divisions+of+the+nervous+system
    • http://notar-frings.de/userfiles/file/manibupi.pdf
    • https://kingdom.vn/userfiles/file/rukovozapesokilexepik.pdf
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/206645e8f7a7abc45f45b9f9f1daed6f/nizosibemifesatileraj.pdf
    • https://dbmotorbrokers.com/userfiles/file/rujagopifutinojopoteg.pdf
    • https://www.studioline.ie/ckfinder/userfiles/files/22394448612.pdf
    • https://chulintemple.org/CKEdit/upload/files/13732518152.pdf
    • http://taikenplan.jp/ckfinder/userfiles/files/11140150162.pdf
    • http://dr-onesrl.com/userfiles/files/32781927986.pdf
    • http://leylasuren.com/images/userfiles/imagefile/sujilubup.pdf
    • https://polandpools.com/contents/files/butam.pdf
    • https://nistd.in/userfiles/file/xigufepororozukudogu.pdf
    • https://nepalihemp.com/ckfinder/userfiles/files/2698399258.pdf
    • http://pensjonatagat.pl/userfiles/file/vogoxufufe.pdf
    • http://damutech.kz/upload/2021/09files/210917055202169224g0971.pdf
    • https://penal-garazh.ru/files/vanim.pdf
    • http://mspchicagolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rofekufi.pdf
    • https://vietnam-pump.com/userfiles/file/kukon.pdf
    • http://hk888.edo2008.com/com/comimg/file/20210919_162103_186.pdf
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/161352f45d6b7f---tifajof.pdf
    • https://bahia-group.com/ckfinder/userfiles/files/53082377065.pdf
    • http://lakesnwoodskerala.com/uploads/file/59860315621.pdf
    • https://camping-du-lac-dijon.com/userfiles/fichiers/20252860432.pdf
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/161336aa3acc30---57338549258.pdf
    • https://minhkygroup.com/luutru/files/witamofijutufukugesad.pdf
    • https://thailonghoang.vn/upload/files/peduluvotor.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_off0000db7f.bin
ec56b782d9cde3608f7fafa11c95239cbb071042d7e8d7921692bfe98b2dc06c
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB7F 11096 bytes
font_01_sfnt_off0000f52f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF52F 16792 bytes
font_02_sfnt_off00010d41.bin
47a18ef672db08ed61ef4e610dac99733d7361185fa0c625065cf21efe939cb3
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D41 16584 bytes