Malicious PDF — malware analysis report

Static analysis result for SHA-256 81df7dc828f7948c…

MALICIOUS

PDF

88.0 KB Created: 2021-07-23 02:56:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: dbce7db4e71d569d2adb1b8c25e86c5b SHA-1: 8711599c896707b0eb16a0cd6d4edd0300efbceb SHA-256: 81df7dc828f7948ca80ffb2bb648d71fcb1ca4d48809b4cf3f2bd778e4dddbcd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, containing numerous embedded URLs that point to various websites. Several of these URLs are hosted on compromised WordPress upload directories or other disposable hosting, suggesting an attempt to distribute malicious content or phish users. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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 http://wijnhuis-vaessen.nl/site/data/ws/files/likujewixiwodonivuso.pdf In PDF document text
    • https://uleshuzatabc.hu/files/file/miwepuxinufi.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/cefdc0a1602604fc1d6fc5856c44d056/zunudotupalezadide.pdfIn PDF document text
    • http://stringquartet.biz/web/images/fck/file/dewit.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210518072258.pdfIn PDF document text
    • http://geometramaurotozzi.it/userfiles/files/2586325331.pdfIn PDF document text
    • https://arerp.kr/data/file///88249487132.pdfIn PDF document text
    • http://casaatlantida.com/userfiles/file///10425384130.pdfIn PDF document text
    • http://myconnect-thailand.com/image/upload/File/45564978578.pdfIn PDF document text
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/icnnjpflc7ek9b9opfdhlmt46j/suvalifakofaxomo.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/98fc0a468b4e2120a9dc584d8406c408/68388487209.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/8r62amdl094c1lbk86r8gkkavl/98434081415.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/25377305945.pdfIn PDF document text
    • https://bharatbiodiesel.com/userfiles/file/11672665828.pdfIn PDF document text
    • http://legalinet.eu/userfiles/files/vawixiledore.pdfIn PDF document text
    • http://cy2hand.com/userfiles/poraxuw.pdfIn PDF document text
    • http://dangkykinhdoanhkiengiang.com/upload/ck/files/19329527006.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a418a8b8474---54340614395.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b6136841818---79049010180.pdfIn PDF document text
    • http://aeronautike.com/userfiles/file/xudowebisaresazipuda.pdfIn PDF document text
    • http://abacusnancy.com/userfiles/file/51174495076.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/wagozuvizap.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=people+source+placement+servicesPDF link annotation
    • 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_off0000f2c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2C9 17492 bytes
SHA-256: d67fa6d8c5408135a782a4a1b9b7169e87f588bbbf8e1ed6f984feaa77162f06
font_01_sfnt_off000120bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120BC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000138d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138D3 10700 bytes
SHA-256: 7019207d09980568455f8fa4f15ed2fade47499ce49a6e35e16461fcc1354383