Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f3534775422a83e…

MALICIOUS

PDF

88.6 KB Created: 2021-09-20 11:05:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 055fe13631accd6e1e957b77bf848c8d SHA-1: ea7df2f19592a035f4b0c7bde7c68fc1d7e54a90 SHA-256: 8f3534775422a83e5aea9aca46a7a6b7c750a82593aabc1bdccee4d419932e97
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed for malicious redirection. ClamAV and ML classifiers confirm its malicious nature, likely as a phishing or malware distribution lure. The presence of multiple external URIs and a link farm structure suggests an attempt to exploit users by directing them to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

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://cructi.ru/uplcv?utm_term=herbert+schildt+java+the+complete+reference+ninth+edition
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16136bb18df72f---35381711282.pdf
    • http://agriturismolataggiasca.eu/userfiles/files/43535912278.pdf
    • http://yigang-lin.com/uploads/files/202109141428289902.pdf
    • https://butagallery.com/userfiles/files/37642457738.pdf
    • http://dunajecbiala.pl/upload/File/nepubota.pdf
    • https://congnghiepxd204.vn/upload/files/vamujafuf.pdf
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/6d75f03739b609526af4dd6aed748a2b/rijeruvumisi.pdf
    • http://chiari-web.com/ckfinder/optimist/files/marurinipesoramu.pdf
    • https://hoanghaie.com/Images_upload/files/73056977742.pdf
    • https://cafesca.mx/ckfinder/userfiles/files/nopixa.pdf
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613fe6db0f66e---47671059933.pdf
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/38e3fb1f19b8f6f17ac5a38f9a190577/53362230238.pdf
    • http://neoneophytou.com/ckfinder/userfiles/files/padaverabevujijef.pdf
    • https://pasifikendustriyel.com/userfiles/file/budaparuradopajonedev.pdf
    • http://archgeo-leszno.pl/uploads/userfiles/files/20394001965.pdf
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613196111279b---47771964634.pdf
    • http://bhhangkhong.com/upload/images/files/84064943421.pdf
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/22344dff26be084c9f6d3d4b667dae32/sojipebusotema.pdf
    • https://watosaphotography.com/app/webroot/userfiles/files/20210909_125344.pdf
    • http://vina2002.com/uploads/files/vixojofoji.pdf
    • https://jamisonfurnace.ca/userfiles/files/75059634653.pdf
    • http://bhhangkhong.com/upload/images/files/81563719734.pdf
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/68f68ee0cfce989b83822330de0f3a85/90127471232.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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc8e.bin
fddcbe21bdf9fb2753729b4ab5b26d7a3fbb01e3fe51d41ab0725360e25c189d
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC8E 16244 bytes
font_01_sfnt_off0000e278.bin
44e1b142c2be73809ecd3843942ebeeab32fb7d560cc43278127acc78a01177d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE278 21424 bytes
font_02_sfnt_off0001190f.bin
51ee95b19c26a2a02e4d6be1f54818d88f24b4bf62865ae3f49ccb69f9680e80
pdf-font-stream PDF embedded font (sfnt) at offset 0x1190F 11212 bytes
font_03_sfnt_off000132ce.bin
9c928bf144e3eec6b0e52ae2bba533670589b2228405e28e178bb89e049a64b1
pdf-font-stream PDF embedded font (sfnt) at offset 0x132CE 1684 bytes
font_04_sfnt_off00013aca.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13ACA 16792 bytes