Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a3e81243082ad9c…

MALICIOUS

PDF

69.2 KB Created: 2021-09-30 12:27:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: c7ce9f93bf3d3caaa67e571fb9cca304 SHA-1: c2a01dbec756626e7e346957e5331c8c4e8932fb SHA-256: 8a3e81243082ad9cefef397767e57af3dce5886d33e9170fbdc4d25ca62d1f5e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many of which point to compromised WordPress sites or disposable hosting, suggesting a phishing or spamming campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to malicious content or phishing pages. No scripts were extracted, but the structure and URL patterns are consistent with a link farm used for malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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=how+to+save+reels+video+in+gallery PDF link annotation
    • https://linhquan-group.com/upload/ck/files/57633567680.pdfIn PDF document text
    • http://akvari-um.ru/userfiles/file/tokawejuwoxa.pdfIn PDF document text
    • https://raguvosbaldai.manovonia.lt/images/files/bapimi.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/4feefd52271dea08e38e4bba797122d8/vonegu.pdfIn PDF document text
    • http://www.toptehnik.si/images/79938849119.pdfIn PDF document text
    • https://coolinterier.sk/upload/files/1299769439.pdfIn PDF document text
    • https://vaitinhdien.com/app/webroot/upload/files/42196843828.pdfIn PDF document text
    • http://solarhomepage.ch/fckeditor/editor/images/file/lokokufuwenol.pdfIn PDF document text
    • https://webtechnocrats.com/upload/file/vamemejuwirulegibupetojaw.pdfIn PDF document text
    • http://holland-ex.com/images/blog/file/95696139071.pdfIn PDF document text
    • https://otterdisplay.com/userfiles/file/56066448354.pdfIn PDF document text
    • http://xn----7sbicwad4afgcgd5aph7d5e.xn--p1ai/ckfinder/userfiles/files/wokafaxurus.pdfIn PDF document text
    • https://losaltos.com/wysiwygfiles/file/39955084849.pdfIn PDF document text
    • http://tnslib.su/userfiles/files/26508498245.pdfIn PDF document text
    • http://zge-led.com/luodan/images/userfiles/file/jutagogudujigekerim.pdfIn PDF document text
    • http://er-trans.com/img/produkty/files/dojukudivevukamajegabex.pdfIn PDF document text
    • http://nuitsdartistes.eu/images/file/zefogij.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1614e90bd8285e---89232781640.pdfIn PDF document text
    • http://twapp.freshkon.com/upload/files/47449926239.pdfIn PDF document text
    • http://hejia-ele.net/upload/39264528079.pdfIn PDF document text
    • http://bannermaul.com/userData/board/file/27190338280.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148305cb5ad5---zamapamuze.pdfIn PDF document text
    • 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://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/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_off0000af93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF93 15320 bytes
SHA-256: a6db55e1dd4f27142b7780e6e29a591ed1683a4cf251ac19a37fa357b5560120
font_01_sfnt_off0000d66a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD66A 10680 bytes
SHA-256: 2ef90e485836e23b977373080987215ac13217b7245dc4cb575236f499a7a729
font_02_sfnt_off0000eed5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEED5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1