Malicious PDF — malware analysis report

Static analysis result for SHA-256 db25082b289a3811…

MALICIOUS

PDF

44.5 KB Created: 2020-08-30 08:30:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 231274d830b0d43ad380b3a7214a5b0e SHA-1: 4179fcedff86c5aac2f2bad589d5ec5c8f120b07 SHA-256: db25082b289a381169f6d5f11ee2ab4ce2ebf0d3609124af6f93b45af5f48454
154 Risk Score

Malware Insights

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

The PDF file contains a malicious redirector link disguised as a resignation letter for health reasons. The heuristic PDF_MALICIOUS_REDIRECTOR_LINK indicates that the embedded URL points to known malicious infrastructure. The ML classifier also strongly flagged this PDF as malicious. The document body contains the lure text and the malicious URL.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • 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.ru/wix?keyword=resignation+letter+for+health+reasons+pdf
    • https://cdn.shopify.com/s/files/1/0437/2476/7400/files/xevugirudubelijinov.pdf
    • https://cdn.shopify.com/s/files/1/0428/8059/8172/files/florida_algebra_1_eoc_practice_test.pdf
    • https://cdn.shopify.com/s/files/1/0432/3019/9966/files/3934628844.pdf
    • https://static.usrfiles.com/ugd/10b11f_6e7f005362bf4ef09c9649edc0de5ee5.pdf
    • https://static.usrfiles.com/ugd/b8c837_1f9ff7e07b7c4672abda1fc655df6630.pdf
    • https://static.usrfiles.com/ugd/b8c837_4f9d7878fc5d424aa2ad22b1841f14e4.pdf
    • https://static.usrfiles.com/ugd/b8c837_439ca287ba404a629e4fd1e99a16ca19.pdf
    • https://static.usrfiles.com/ugd/5b9365_2d005ba84d224bbfbb2cddb4ca560209.pdf
    • https://cdn.shopify.com/s/files/1/0431/8344/0030/files/dibukepevesez.pdf
    • https://cdn.shopify.com/s/files/1/0429/2716/1507/files/70877263910.pdf
    • https://cdn.shopify.com/s/files/1/0433/4977/0395/files/83955164299.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/damegadunuje.pdf
    • https://cdn.shopify.com/s/files/1/0432/6971/8182/files/osmosis_and_tonicity_coloring_worksheet_answers.pdf
    • https://cdn.shopify.com/s/files/1/0430/3123/2661/files/rolux.pdf
    • https://cdn.shopify.com/s/files/1/0437/1618/2184/files/pdf_watermark_remover_apk.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/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000704a.bin
fd1badd8ac02b8c6005e453c8819e083928d40b8566dffc6381db6a383d16127
pdf-font-stream PDF embedded font (sfnt) at offset 0x704A 5308 bytes
font_01_sfnt_off00008253.bin
8ecb7d9dde0b1dffd82855f20279762f31e321e3cdcd7b686cd984b4551a26dc
pdf-font-stream PDF embedded font (sfnt) at offset 0x8253 10340 bytes