Malicious PDF — malware analysis report

Static analysis result for SHA-256 399876a762791869…

MALICIOUS

PDF

69.8 KB Created: 2021-09-14 09:09:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 652ec8da3acd408005fd875e85c4a49b SHA-1: 2582975cff39690dbcb6e426a4d36cb0973c14ee SHA-256: 399876a762791869d7279761490012579a1ba86520590c45271d52dab8f8c80e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains a link farm pointing to various domains, including compromised CMS uploads, suggesting an attempt to redirect users to malicious sites. While no scripts were explicitly extracted, the nature of the link farm and the PDF format itself often implies the use of embedded JavaScript for redirection or exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://inwebjor.ru/uplcv?utm_term=minecraft+pe+official+apk PDF link annotation
    • https://harkakotony.hu/UserFiles/file/85721675162.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/285824050affb8596adb5486316ef1ee/dolatoraliputoriwexumi.pdfIn PDF document text
    • https://hotellemaritime.com/hotel/upload/files/20994415557.pdfIn PDF document text
    • https://dyaa.club/uploads/file/33889996694.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/013f1b31f425161202478510caf2eab7/lumofumemelex.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/16134e90cd175c---48316064365.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/xujasadenapevepajote.pdfIn PDF document text
    • http://eg-connect.com/uploads/editorfiles/file///22185631618.pdfIn PDF document text
    • http://traiteurluc.com/userfiles/file/sozetakokugeripovaw.pdfIn PDF document text
    • https://santehsevast.ru/userfiles/files/88734855851.pdfIn PDF document text
    • http://askaudit.ru/price/tolinerilavux.pdfIn PDF document text
    • http://bielle-srl.com/userfiles/files/kopeselusomof.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/71h1bqfgg0ghou4np9c7huben4/37612563393.pdfIn PDF document text
    • http://firesecurity.sk/userfiles/file/97427085100.pdfIn PDF document text
    • https://gsm.company/ckfinder/userfiles/files/fanadakeka.pdfIn PDF document text
    • https://flour.co.uk/ckfinder/userfiles/files/jefadebujajatejukefu.pdfIn PDF document text
    • http://cppzone.ru/users/blogs/file/nowanawelagadojugimorika.pdfIn PDF document text
    • http://www.samuitns.com/image/upload/File/matujejazoxunite.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/ihvr038hj8q9gu03et9m85vt57/21157439547.pdfIn PDF document text
    • https://csmgh.net/pevron/www/img/file/91917477915.pdfIn PDF document text
    • http://topas.lt/userfiles/file/wifokusejozugoz.pdfIn PDF document text
    • http://inspiredindianfoundation.org/uploads/91689842823.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_off0000b24c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB24C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA5E 15620 bytes
SHA-256: 56d209405e9f9dbed9e3d71bc0d4fbaef0be51346bc4b7e062ba268103d34d9b
font_02_sfnt_off0000f21f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF21F 10388 bytes
SHA-256: c9f47f5a77908ee4039aefa86c20825368aaf4bef80d94daefd01834c8e6c3bb