Malicious PDF — malware analysis report

Static analysis result for SHA-256 64f08d33ddac490b…

MALICIOUS

PDF

37.1 KB Created: 2020-08-17 13:55:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 50857a1046b158ab2e9b22caade32cdb SHA-1: c3609eae536091b8868aa964976749ac953262f2 SHA-256: 64f08d33ddac490bbfb4c7c839f2402f54da41fb740ac08e695c55557cad8420
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded links, many of which point to a redirector service. The document body text, though corrupted, suggests a lure related to 'worksheet answers', and the primary malicious URL is a redirector designed to lead users to potentially harmful content. The ML classifier strongly indicated maliciousness, and the PDF structure itself is flagged for containing a mass external link farm.

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.com/pify?keyword=equivalent+expressions+independent+practice+worksheet+2+answers
    • http://files.thewea.org/uploads/1/3/1/8/131856446/0b6869be1.pdf
    • http://zusotagub.ascend111.com/uploads/1/3/0/7/130776433/35c49759b9d08a0.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.opentle.org
    • https://cdn.shopify.com/s/files/1/0438/2212/1122/files/37963973089.pdf
    • https://cdn.shopify.com/s/files/1/0433/2103/2859/files/xuvizavofabajak.pdf
    • https://cdn.shopify.com/s/files/1/0428/2197/6220/files/72707431275.pdf
    • https://cdn.shopify.com/s/files/1/0430/9280/3744/files/41101337748.pdf
    • https://cdn.shopify.com/s/files/1/0434/4155/3575/files/bupuvusebunawimot.pdf
    • https://cdn.shopify.com/s/files/1/0431/4651/0504/files/discord_writing_commands.pdf
    • https://cdn.shopify.com/s/files/1/0428/0143/0695/files/18929228210.pdf
    • https://cdn.shopify.com/s/files/1/0431/8468/5224/files/giwinumawi.pdf
    • https://cdn.shopify.com/s/files/1/0438/4060/2269/files/patent_ductus_arteriosus_2020.pdf
    • https://cdn.shopify.com/s/files/1/0434/6888/2072/files/raluwesagoxasugizojo.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://scripts.sil.org/OFL
    • http://www.gnu.org/licenses/gpl.html

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000042fa.bin
41f00212674565add16b3cfd2bceebb77485c4d7f785cf2c2b8b6ebd216934e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x42FA 5660 bytes
font_01_sfnt_off00005644.bin
7a02da73c5ff24218d04b188db7d31ceb9303d5dedd43b645f18a615a19d9b6a
pdf-font-stream PDF embedded font (sfnt) at offset 0x5644 6068 bytes
font_02_sfnt_off000065f4.bin
ff9ef3013b7cb57531b6cf100f1e92733456ca3461475745f7d20f591631c630
pdf-font-stream PDF embedded font (sfnt) at offset 0x65F4 9568 bytes