Malicious PDF — malware analysis report

Static analysis result for SHA-256 f31b821477834479…

MALICIOUS

PDF

108.0 KB Created: 2021-08-11 20:21:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 6bade32e6ba851158dc90c9550360aea SHA-1: 9607429c7808345be201973b815ff9df65ff62cd SHA-256: f31b821477834479958e8df75b0f39634c0681aa711f14cf0792785df438bde5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to compromised WordPress upload storage. While no scripts were directly extracted, the presence of numerous links to potentially malicious PDF files suggests a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a614bd08813---35722753736.pdf In PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6641be6a22---saxidunusogasovuzitas.pdfIn PDF document text
    • http://chiengthai.com/file_media/file_image/file/1815255480.pdfIn PDF document text
    • http://massarentearchitettura.com/userfiles/files/74062099324.pdfIn PDF document text
    • https://www.hotelamoha.it/wp-content/plugins/formcraft/file-upload/server/content/files/160eca41aabcda---vobibewipusilurum.pdfIn PDF document text
    • http://hpc1970reunion.com/clients/3/3e/3eb4c5728feca7eb79feed4eed44c519/File/wopof.pdfIn PDF document text
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/c8e37237fede876b85f3c24e3e136ad7/dugiwesugasobosuzijekuz.pdfIn PDF document text
    • http://rutka.pl/media/upload/files/1a8ed066fc58a6c0788240836bda745b.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/72e3f45778b2baa28d1479debca18ea5/44198406159.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16090fd0490ccd---40516102660.pdfIn PDF document text
    • http://centrons.com/uploaded/file/113872025160f735975dc2e.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/e419fde8bc2b575539c56f023b5a880d/danadaw.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afdee88f0c7---kenugukuzepanumepavimamo.pdfIn PDF document text
    • http://bethtikvahevents.ca/clients/2/20/20a91c0cb94b02964b0d1c5d980f1596/File/firamililoxozowigafesofej.pdfIn PDF document text
    • http://dedanskecasinoer.dk/userfiles/file/70046230272.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/a6cd2c80697f9e7d83c46228a348f209/xugilanakawu.pdfIn PDF document text
    • http://julianina.dk/upload/file/jazes.pdfIn PDF document text
    • http://tasarimak.net/ckfinder/userfiles/files/tilarotuwiz.pdfIn PDF document text
    • http://dalaichau.com/files/mitexelixedegefonagido.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e84f78f52d---pazakupaji.pdfIn PDF document text
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092b3a43dac8---fedufulitawiviwa.pdfIn PDF document text
    • http://donahoelawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jepavodikiwafekedezo.pdfIn PDF document text
    • https://bibliothequeanglaise.org/upload/files/nugitogimid.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/160847049a9588---92959837228.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=batman+the+dark+knight+movie+in+tamil+free+downloadPDF 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_off000142c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142C6 17568 bytes
SHA-256: bc108bcda0b4bc098f6fdf68bf7749e3421f2ac9ccb13f71ffb5191012854297
font_01_sfnt_off00017049.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17049 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00018860.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18860 10928 bytes
SHA-256: 487a8e4a2eb13648f11fe47774d9de5de35913842c4dd735328319e856d094a3