Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3281eb68ad6c322…

MALICIOUS

PDF

42.6 KB Created: 2020-08-11 09:04:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d81bdb4aa7ac41349532322756a50eea SHA-1: 6c3c32a177e8d894a7ce4f3cd7e08d458e239959 SHA-256: a3281eb68ad6c322140fb9b7c486c867599cd42110e34a9c2b5e3c9976aafbc8
152 Risk Score

Malware Insights

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

The PDF was flagged by multiple critical heuristics for containing malicious redirector links and a link farm. The ML classifier also strongly indicated maliciousness. The primary malicious IOC is the redirector URL, which is likely used to funnel victims to phishing or malware sites. The document body, though heavily obfuscated, contains references to URLs that are part of this 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.cc/wb?keyword=hamlet%20book%20pdf%20modern%20english
    • http://gawowu.nushagakfurcompany.com/uploads/1/3/1/0/131070786/4427135.pdf
    • http://files.williamsburgrec.com/uploads/1/3/2/6/132682745/tagogumolizim_fofuzipupi.pdf
    • http://files.stonebeltsupply.com/uploads/1/3/1/8/131856129/rameridotegulig.pdf
    • https://cdn.shopify.com/s/files/1/0435/1016/9759/files/migujerusunamekurigevuko.pdf
    • https://cdn.shopify.com/s/files/1/0427/7361/0663/files/9325281061.pdf
    • https://cdn.shopify.com/s/files/1/0433/9620/2659/files/branches_of_social_science.pdf
    • https://cdn.shopify.com/s/files/1/0435/4896/7061/files/mireziriv.pdf
    • https://cdn.shopify.com/s/files/1/0438/1877/8781/files/south_african_constitution_book.pdf
    • https://cdn.shopify.com/s/files/1/0443/3071/3244/files/cashflow_101_board_game_rules.pdf
    • https://cdn.shopify.com/s/files/1/0431/0905/6666/files/nafonekifi.pdf
    • https://cdn.shopify.com/s/files/1/0428/2961/1171/files/minecraft_mob_grinder.pdf
    • https://cdn.shopify.com/s/files/1/0431/1161/2572/files/nazexiv.pdf
    • https://cdn.shopify.com/s/files/1/0434/2412/0984/files/dynamic_dns_free.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_off0000685e.bin
d09b01ca627bdb7d5e24ed9a7c53c28ff7cec3bd123b33ff12e0b6a886fea867
pdf-font-stream PDF embedded font (sfnt) at offset 0x685E 5620 bytes
font_01_sfnt_off00007b46.bin
19d9672cdddf0cd4d722c937e8df088cab29370195ef4e0a2ef8f9204b83f5e0
pdf-font-stream PDF embedded font (sfnt) at offset 0x7B46 10132 bytes