Malicious PDF — malware analysis report

Static analysis result for SHA-256 36d7386e401afc78…

MALICIOUS

PDF

61.7 KB Created: 2020-07-19 22:33:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: 2d1036dfaa7a8c73a6775706bb338b07 SHA-1: a9412fce7fb75a6f5a137670786091fc42ab443a SHA-256: 36d7386e401afc7826c7b9fbc7676083409e9d61baeaae91db7627a2b9cf867a
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains numerous embedded URLs, with the primary one identified as a malicious redirector. The document body, though heavily obfuscated, suggests a lure related to 'maths formulas' to entice users to click the malicious link. The ML classifier strongly indicated maliciousness, and the PDF structure itself contains a link farm, further supporting a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://ttraff.com/wb?keyword=important%20maths%20formulas%20for%20ssc%20cgl%20pdf In PDF document text
    • http://files.plainjane614.com/uploads/1/3/1/6/131606396/0550115.pdfIn PDF document text
    • http://files.jerniganlandscaping.com/uploads/1/3/2/7/132712407/b25c3af9a2d9f0.pdfIn PDF document text
    • http://files.nmfwa.org/uploads/1/3/0/7/130775838/jeronazemesavov-navorokidixek.pdfIn PDF document text
    • http://files.esteemedk9.com/uploads/1/3/0/7/130739126/2259636.pdfIn PDF document text
    • http://files.shinechiro.com/uploads/1/3/1/3/131379409/denunipen_nerebibo_wilag.pdfIn PDF document text
    • http://files.ketonetpasim.com/uploads/1/3/1/3/131382346/nenidebejifaso.pdfIn PDF document text
    • http://files.retreatjourneys.com/uploads/1/3/1/3/131380875/nunedozotuzuxada.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://nobusaxox.files.wordpress.com/2020/06/78941042408.pdfIn PDF document text
    • https://pijadajetami.files.wordpress.com/2020/06/5974012359.pdfIn PDF document text
    • https://bujiwilofife.files.wordpress.com/2020/07/metoduzujo.pdfIn PDF document text
    • https://nowigunuki.files.wordpress.com/2020/07/kigujefigokeguje.pdfIn PDF document text
    • https://posirosinuda.files.wordpress.com/2020/06/50460150031.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/63016720996.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/4347/1003/files/rigisirukudigemuvobetik.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0439/0970/9976/files/2000374120.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/3088/8094/files/kozirixexosi.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/2898/7547/files/40636026680.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/6993/9607/files/fuwosigogamivopisaxotuku.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/6395/1003/files/48847120501.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/3685/9813/files/nobinipubegiwupatubu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0436/5382/4677/files/53381817980.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000a819.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xA819 5224 bytes
SHA-256: 1e3f7372a99240eba0e508507861174989081ba6b76d59e1366d8ad41ce1964d
font_01_sfnt_off0000b992.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB992 15008 bytes
SHA-256: dba4076b7dbf6d41171db55fe11a143c865964b8e38f64985bb903a6d186523d