Malicious PDF — malware analysis report

Static analysis result for SHA-256 f820171daeb9cf7a…

MALICIOUS

PDF

82.3 KB Created: 2021-06-26 15:55:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 7c4faefb37d7ae74670cf4af5b10d55a SHA-1: 342025f28a0adb93f92948230efc80269e0ebb95 SHA-256: f820171daeb9cf7a85565ca35a0c3596704fcbb7c24633d753ea68feb9a09adc
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous URLs pointing to compromised WordPress upload directories. These links likely serve as lures for phishing or to distribute further malware payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607b81705dd42---22014614218.pdf In PDF document text
    • https://inncredel.com/uploads/52163647799.pdfIn PDF document text
    • https://haysalon.com/public_html/userfiles/file/sijujaliwokot.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/ca869b83d357a22cb13f46ae761fbe79/nimawipesotil.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a84e4c2c723---lanonagojirag.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/gejumibemitetifaxad.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/piv75k0vcr746b8j4g7hvl2f7v/bobaxoziginugisuxolam.pdfIn PDF document text
    • http://bitite.lv/media/txt/122/file/358794947.pdfIn PDF document text
    • https://dienlanhbachkhoa.info/upload/files/dixamodurite.pdfIn PDF document text
    • http://envigest.cz/upload/file/fuwixogujubezejo.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c8944abf65e---fufekawibonuralobafumu.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/aeb0ac67752f09e103353d1d5a538df4/75762651182.pdfIn PDF document text
    • http://billsky.ee/files/file/64337404974.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/0c7b512e21dd001cb5727850a41603d7/kuwobisodinatuzuliraza.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160cdcfbfaff48---zivuselaworofutit.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607075a97483a---mapemufexepabefixebirulu.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/8d56060f4041e2040830ce63c9d93692/dasax.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=nabothian+cyst+meaning+in+tagalogPDF 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_off0000e10a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE10A 10808 bytes
SHA-256: ec0cfc8545d5be4ad81f17191a8900dd97f26c4db7183022ebaf3ce22e2687ef
font_01_sfnt_off0000f9d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9D0 16436 bytes
SHA-256: c30aa2258a4bc8e8d817b3bdcd07bcb4621e7c7c3d3305407b945d14bd0f9767
font_02_sfnt_off00012456.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12456 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1