Malicious PDF — malware analysis report

Static analysis result for SHA-256 c9b7574106683f1c…

MALICIOUS

PDF

95.1 KB Created: 2021-07-27 09:04:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: b6b29ac533216e6a5769e2f2d8faa072 SHA-1: de24f99e80ad779a7fe2a8f23c93a09e6678c259 SHA-256: c9b7574106683f1c1c9a04328e73a7ed1ca5e3719afcc4a720d3092d0557406c
116 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URIs, many of which point to potentially compromised websites or link farms. The ML classifier strongly indicates maliciousness, and the presence of multiple 'PDF_URI_IP_LITERAL' and 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristics suggest an attempt to obscure the true destination or leverage low-reputation hosting. The document body is heavily obfuscated and unreadable, providing no direct clues to its intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://almuhja.ps/ckfinder/userfiles/files/48102877366.pdf In PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/dea1bd762ea773e3ce4c5899c07eea48/44829154665.pdfIn PDF document text
    • https://yasacompany.com/upload/files/29259227534.pdfIn PDF document text
    • http://polymer-optix.de/userfiles/file/befanivazeretuxoz.pdfIn PDF document text
    • http://raczcsalad.hu/files/ropujuvisujoj.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/1609bdc7e6807e---piziwopenefiba.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/ranepajazidujiwil.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098703871242---20632417794.pdfIn PDF document text
    • http://transchem-tech.com/Uploadfiles/files/pofunojagex.pdfIn PDF document text
    • https://svarovanijelinek.cz/ckfinder/userfiles/files/jadarejubodakudojexomubus.pdfIn PDF document text
    • https://www.stjohnhomelessshelter.org/wp-content/plugins/super-forms/uploads/php/files/4f58edb75d951fb42ee4cea8a4cf411d/fobizozilogelusutubi.pdfIn PDF document text
    • http://grappin-annat-como.com/userfiles/grappin-annat-como.com/file/39902907784.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/qktofvho0aop3ub9b942upsis2/silewematuvosotijade.pdfIn PDF document text
    • http://asupuro.com/upload/save_image/files/60587675036.pdfIn PDF document text
    • http://tandartsindex.nl/images/uploads/tivududewikav.pdfIn PDF document text
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/1609ee19c8bc27---18460678016.pdfPDF link annotation
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/ntrbdilaju1qvrr2ab3704q4n5/1017046075.pdfIn PDF document text
    • http://i-daa-wl.de/userfiles/47953424252.pdfIn PDF document text
    • https://geneolock.com/locktactyuma/userfiles/file/7384985713.pdfIn PDF document text
    • http://elite-weekend.com/clients/9/94/945a7f92a07ecc721aac768ad340748a/File/12535510275.pdfIn PDF document text
    • https://isosklo.cz/uploads/zokamivogaze.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607865f59c06b---38661984732.pdfIn PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/vugatoromob.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fec71af33e4---92171242970.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=huawei+bootloader+unlock+free+apkPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_007_off00013a56.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x13A56 17440 bytes
SHA-256: 94445edcf5839199b58ddc76270ddbf9ab688a499b422240e039b95b9ada0471
font_00_sfnt_off0000f3c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C3 17620 bytes
SHA-256: 98f591fe6a72d50b0d20937b77051ff282df4d91da462345a99cab0885d35ba3
font_01_sfnt_off00012245.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12245 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off00015491.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15491 10852 bytes
SHA-256: 7298acc18c0e75c5d4e628e90ce8918fabbd865fc1a868d8ce113592700811d0