Malicious PDF — malware analysis report

Static analysis result for SHA-256 1384c965814437aa…

MALICIOUS

PDF

80.1 KB Created: 2021-09-18 03:33:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4a6cf4e5ae0e3d87af5f0b68e5fdf23e SHA-1: 9ee5256f755c131d9451ade4c8f3a0fa5fc3178a SHA-256: 1384c965814437aae68bffa9bd5896ac227a6a29c71de9cdf347699f1fbe4050
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier strongly flagged this PDF as malicious, and the heuristic firings support the presence of a link farm. No scripts were extracted, but the overall structure suggests a malicious intent to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 5

  • 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://crewmak.ru/uplcv?utm_term=download+android+drivers+for+windows+xp PDF link annotation
    • http://nissanotogovap.vn/uploads/images/files/65237175582.pdfIn PDF document text
    • http://daltan.hu/userfiles/file/bugizawotenugobupanudo.pdfIn PDF document text
    • https://cahayaapi1.com/contents/files/zuxukimedebo.pdfIn PDF document text
    • http://hongshengfish.com/uploadfiles/2021091023383922448.pdfIn PDF document text
    • http://dogomanhnghia.com/uploads/files/xafuselumedezafe.pdfIn PDF document text
    • https://inunekocp.jp/mailmagazine/upload/files/kufasofafugugipowix.pdfIn PDF document text
    • http://filippodelvita.com/demo/userfiles/file/paxesefatugobebo.pdfIn PDF document text
    • https://gimenezricarte-deltabogados.com/ckfinder/userfiles/files/25517614618.pdfIn PDF document text
    • http://elementyzlaczne.pl/media/file/sezutiwironaregu.pdfIn PDF document text
    • https://xn--72ca1bzcdf9cg5df4n5a8cei.com/userfiles/files/70079296994.pdfIn PDF document text
    • http://stapper.de/sites/default/files/userfilesfile/93324859970.pdfIn PDF document text
    • https://membermimpi.com/contents/files/vujadipo.pdfIn PDF document text
    • http://self119.net/upload/userfiles/2021/09/files/210918001418.pdfIn PDF document text
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/6fc787147a58dd0d6891f04b70abba1f/86218916988.pdfIn PDF document text
    • https://stiglic.sk/userfiles/file/15488527914.pdfIn PDF document text
    • https://batdongsandothanh.vn/luutru/files/wonegidawo.pdfIn PDF document text
    • http://pho32shabu.com/uploads/files/66443430978.pdfIn PDF document text
    • http://budka39.ru/files/babusisulojelet.pdfIn PDF document text
    • http://loscogliodifavignana.it/userfiles/files/dasejotogixerajane.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138330c717a4---ronoxofewonelanalibavilib.pdfIn PDF document text
    • http://fuyu.010bi.com/ckfinder/userfiles/files/61637902236.pdfIn PDF document text
    • http://capmar.eu/userfiles/file/82528790594.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/kcjp53q6voev082q22f7pec643/39828251057.pdfIn PDF document text
    • http://ketphatthinh.vn/upload/files/jaforinofolafinuzowur.pdfIn PDF document text
    • https://chiataiec.com/userfiles/Proj_Name/files/rifamimuve.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/9fef8b6cd5e0c4bb86199d70e34bcfce/203587653.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_off0000d76d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD76D 16360 bytes
SHA-256: 1939c6c7b3d7b65fb90d7008b3ef91b807fadd3d5380a5ea1a64cb6a4a61df0d
font_01_sfnt_off000101d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101D1 10648 bytes
SHA-256: 8a04675226b6a16ab0fa1e03d83025bd9c3992aea7b2045862623aaf6ee2ba9e
font_02_sfnt_off00011a5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1