Malicious PDF — malware analysis report

Static analysis result for SHA-256 1573baece6e3cb61…

MALICIOUS

PDF

73.2 KB Created: 2021-09-11 14:03:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 650c0fe6344768015eb3b4848b2c00c9 SHA-1: 05b8d0a2b769186e6eca7ecda993521d2b74fbca SHA-256: 1573baece6e3cb610b8191cd413c0736db719b973d8fa4083691414adc1dfb41
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress uploads and disposable hosting, indicative of a link farm used to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://archism.ru/uplcv?utm_term=how+to+stop+worrying+and+start+living+dale+carnegie+pdf
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/e64e57c2cf2df40dfb114f3d8d976321/begejetopetiromago.pdf
    • http://candybeauty.vn/upload/files/45154469924.pdf
    • http://rbc-bezorgdiensten.nl/upload/33341893925.pdf
    • https://1tlstar.com/storage/uploads/files/guzoxebise.pdf
    • http://aitrans.cn/UploadFile/file/F1202109090831387181.pdf
    • https://elemonbg.com/Files/File/78454489187.pdf
    • http://wamaeassociates.com/images/uploads/originals/file/44383998650.pdf
    • http://metallpress.ru/files/43180710236.pdf
    • http://hsi-international.com/ckfinder/userfiles/files/17861340374.pdf
    • https://hgindustrial.eu/userfiles/files/39509037014.pdf
    • https://jnvhardoi.org/ckfinder/userfiles/files/93863870975.pdf
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16133fbc086af4---1291007850.pdf
    • http://ambulatorioveterinarioscapindandrea.it/userfiles/files/jukisobuwizizaget.pdf
    • http://handbook.hu/upload/page/file/nawimelezalogosovobezefo.pdf
    • http://slbreakingnews.com/ckfinder/userfiles/files/wezalejemepibetafu.pdf
    • http://kapsalonindex.nl/images/uploads/79905067446.pdf
    • http://awkontrakt.pl/ckfinder/userfiles/files/86136943762.pdf
    • http://rubensova16.cz/files/file/jinuwisoratijegize.pdf
    • http://c-six.it/userfiles/files/2348284937.pdf
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b469749b4c---1396629827.pdf
    • http://nrgmedia.hu/files/file/ripivigodudokazij.pdf
    • http://speednewslive24.com/assets/ckfinder/core/connector/php/uploads/files/besirevefufipira.pdf
    • http://lavalnerina.it/userfiles/file/41128549757.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bb59.bin
e06f6854a101b17193998d8b61ac1704fcdd4ba3a9db539b4d4b445bf41932c7
pdf-font-stream PDF embedded font (sfnt) at offset 0xBB59 16416 bytes
font_01_sfnt_off0000e518.bin
dc9d4612941524720471862fb40ad2503660d7be0163406f8784fefa16fa4352
pdf-font-stream PDF embedded font (sfnt) at offset 0xE518 11052 bytes
font_02_sfnt_off0000fed2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFED2 16792 bytes