Malicious PDF — malware analysis report

Static analysis result for SHA-256 961376562cf4c931…

MALICIOUS

PDF

46.5 KB Created: 2020-07-19 14:39:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: a63351d359a45cc6e1653240769482ae SHA-1: 34eb6fc64a10471fd57f9535a367b799cce99232 SHA-256: 961376562cf4c931541136023a4ec1c913fd704de2ca15a3f051b6eeae826aa3
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of embedded links, with one specifically pointing to a known malicious redirector. The heuristic 'PDF_SEO_LINK_FARM' indicates a mass external PDF link farm, suggesting a coordinated effort to distribute malicious content or engage in SEO poisoning. The ML classifier also strongly flagged this PDF as malicious. No scripts were extracted from this sample.

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.cc/wb?keyword=conditional%20probability%20independent%20practice%20worksheet%20answer%20key In PDF document text
    • http://files.sacredvesselacupuncture.com/uploads/1/3/2/7/132741385/2052792.pdfIn PDF document text
    • http://files.pierisproject.org/uploads/1/3/1/3/131398598/660a41e940.pdfIn PDF document text
    • http://files.episcopalchurchonedisto.org/uploads/1/3/1/4/131406365/62ea12a67.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://wibujilena.files.wordpress.com/2020/07/mexuxegiropitubawanotin.pdfIn PDF document text
    • https://kezaxexuzel.files.wordpress.com/2020/06/xegesu.pdfIn PDF document text
    • https://botojime.files.wordpress.com/2020/06/loruxesirubuvobomuzu.pdfIn PDF document text
    • https://jowoxub.files.wordpress.com/2020/07/dolezurafivusevopiveziz.pdfIn PDF document text
    • https://detomanuz.files.wordpress.com/2020/07/94720654721.pdfIn PDF document text
    • https://vipodujenij.files.wordpress.com/2020/06/womajozifiwevov.pdfIn PDF document text
    • https://wexisipifaw.files.wordpress.com/2020/07/59128275827.pdfIn PDF document text
    • https://tidagar.files.wordpress.com/2020/07/86272036744.pdfIn PDF document text
    • https://piviraxiwak.files.wordpress.com/2020/06/75459465668.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/4521/5656/files/75235638876.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/5158/1597/files/sidobezegekariwuxefomaf.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0438/3434/3574/files/risepuxusikepibaz.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/5530/0249/files/vobutolakajag.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/mowelikuzamutaj.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/7025/9357/files/japasimojulabukajaz.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/xomekanob.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0799/1208/files/525616255.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0427/9032/2342/files/zisanekisuf.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_off000075d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x75D8 5372 bytes
SHA-256: e3068841b5363eee5de269347e13dacb82291c95810499eb918969cae31f2dff
font_01_sfnt_off00008827.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8827 10412 bytes
SHA-256: fc0a5d1aab55f5c46b3c7e5d3dc630b9133e0fa2aaa706acd1d9f3f8cf078279