Malicious PDF — malware analysis report

Static analysis result for SHA-256 8852f4c422fce015…

MALICIOUS

PDF

74.2 KB Created: 2021-06-30 19:16:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e09c40bf7e0dac23deedf0e3b1472f63 SHA-1: 74cf751df9573bb4076b5267bda388d4df17fdde SHA-256: 8852f4c422fce015ba24d04a1daa686cc234b72d73505daa29ef8cf9df66ee42
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous links, many pointing to compromised WordPress sites and disposable domains, suggesting it functions as a link farm. This pattern is often used for SEO manipulation or to distribute further malicious payloads, aligning with the 'Spearphishing Attachment' and 'Exploitation for Client Execution' MITRE ATT&CK techniques.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://hohsingfiber.com/ufiles/files/somowozik.pdf
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af6a25396ff---11605248531.pdf
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609caa46884c4---fowegod.pdf
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083a84cca1f7---vaxazimejorukupo.pdf
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/b6709ca35b85559f70f8aac5d46cae35/watutosubamidak.pdf
    • https://licorne-hotel-restaurant.com/userfiles/file/soraporo.pdf
    • https://almoheetmanpower.com/public_html/userfiles/file/xipegosif.pdf
    • https://cplastik.com/data/cms/file/76499086702.pdf
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/bbagtj03jshnvlsu0rf7meu6q8/11375847270.pdf
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b876ac012e2---zagipajuz.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac64ac31eb7---jekirosatonurerimudagomo.pdf
    • http://ssaisarang.com/ckfinder/userfiles/files/wutemukoberunepukop.pdf
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607165630a966---kusakonabediwofov.pdf
    • http://cuuhoatudong.com/upload/files/21426660905.pdf
    • http://rauvuonsach.net/images/uploads/files/61853885834.pdf
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/920f2eee972a34badfec7326e65de0a2/nexunapupugora.pdf
    • https://akvaguru.hu/user/file/93045114464.pdf
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/40ca1e1c26c701e0e23b5dbfd0e1b6b0/bivetikajejuvegajad.pdf
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bee5fd85f07---wesokonep.pdf
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/ffe211fc9c57db2916a372ddb13c57ff/6213989509.pdf
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abbd484fee3---zevenadokitubipikufasix.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=lucky%27s+carryout+on+southern+avenue
    • 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_off0000bf80.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBF80 16792 bytes
font_01_sfnt_off0000d797.bin
2c71f5d9a73bf4197ab56e95bc2704c4bdc4b1506f792b8fd2ed2f67a57a3f09
pdf-font-stream PDF embedded font (sfnt) at offset 0xD797 10552 bytes
font_02_sfnt_off0000efc1.bin
f1f38d6c267e065b0485737741e439772f81ceeed655733f78ab4892b5e729be
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFC1 16804 bytes