Malicious PDF — malware analysis report

Static analysis result for SHA-256 4134da905cbd8216…

MALICIOUS

PDF

78.1 KB Created: 2021-09-02 19:03:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9a28dcc84bba52216a1bccbbf9ff6af8 SHA-1: 954c1284cbdb573baeeb6c6c1b1287edfee6e439 SHA-256: 4134da905cbd821661cd56e9e4521ad15d5ea6d1a22c9a2e7ee00e9f99bd82ad
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, indicating a link farm for phishing or malware distribution. The ClamAV detection and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a malicious PDF designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 7

  • 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 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 http://bulk-supplies.com/userfiles/file/60742080148.pdf
    • http://odessahighschool1970.com/clients/7/70/70263b1be1b93b62200e198143f59f20/File/22546947674.pdf
    • http://hiredriver.com/uploads/assets/files/9283864576.pdf
    • http://www.icareonline.net.au/ckfinder/icare/files/94222217201.pdf
    • https://quimicasorocolor.com.ve/ckfinder/userfiles/files/45448669853.pdf
    • http://k1a.ru/images/files/file/nemojexivujadi.pdf
    • http://stin-verdon.fr/assets/Image/files/xemonuxovafikilajafore.pdf
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160711c8a8fd87---tuwizisa.pdf
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/4mukhre4bvadbksndsarbuj0dc/wupugab.pdf
    • http://allprintusa.com/admin/images/file/welirudolobezamifiniro.pdf
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/3b6a8b245ca1b035a612ffa97f91ff45/80171357206.pdf
    • https://amd-export.com/site/upload/file/80149997377.pdf
    • http://tc-antey.ru/uploads/files/63569206520.pdf
    • http://gfb.it/upload/fck/file/dagarapusafa.pdf
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/b2bc9b608183da5bee75fdf2eaca25e2/6463055208.pdf
    • https://e-lightingcontrols.com/wp-content/plugins/super-forms/uploads/php/files/cd99fc47d2f078acb27e2d59d95a8707/sedofoxizomubivuzatewov.pdf
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b9c04dd2e3---noleriwevipe.pdf
    • http://dolphinkorea.com/files/files/32806068702.pdf
    • https://ijpdua.com/contents//files/81777648155.pdf
    • https://hansenlight.com/UploadFile/files/borojetikeripobuvuxop.pdf
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/f00a853ac10d07fa97fdd32574088762/jegimikototo.pdf
    • https://marathonlaval.com/userfiles/files/33751837550.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=assembly+language+programming+arm+cortex-m3+vincent+mahout+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_off0000c969.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC969 16792 bytes
font_01_sfnt_off0000e17b.bin
4626a9e2a98f8e6ab598267766ebde85a4ba88df24804a195ca10ec4f2f77aec
pdf-font-stream PDF embedded font (sfnt) at offset 0xE17B 17348 bytes
font_02_sfnt_off00010edd.bin
683f79b1b3fc0ce09085aca36cc6a8434130b9c1f5362530d4c8c5f6f44d7404
pdf-font-stream PDF embedded font (sfnt) at offset 0x10EDD 11776 bytes