Malicious PDF — malware analysis report

Static analysis result for SHA-256 b67e33441666e9e1…

MALICIOUS

PDF

40.7 KB Created: 2020-08-07 07:41:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e5edab4316b0dac0da273d9942f3fade SHA-1: 40fb9e2da01f07c9be2028b8b9412ef657356eb6 SHA-256: b67e33441666e9e137ef9e9ace00884e771111562367fd59db34d499021d4992
154 Risk Score

Malware Insights

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

The PDF contains a link farm designed to appear as legitimate PDF downloads, but one of the primary links redirects to a known malicious redirector. The ML classifier strongly indicated maliciousness. The document body text, though garbled, contains keywords related to PDF downloads, reinforcing the lure. The primary malicious IOC is the redirector URL, which is likely used to serve further malicious content.

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/pify?keyword=bengali+to+english+speaking+course+pdf+download
    • http://files.classiccitychef.com/uploads/1/3/0/8/130874192/vadib.pdf
    • http://files.stjohnsatown.com/uploads/1/3/0/7/130739393/1220507.pdf
    • http://files.loesshillsalliance.com/uploads/1/3/2/8/132814463/fe142ae52.pdf
    • https://cdn.shopify.com/s/files/1/0430/0675/4970/files/way_back_into_love_piano.pdf
    • https://cdn.shopify.com/s/files/1/0434/5797/0329/files/grammar_english_oxford.pdf
    • https://cdn.shopify.com/s/files/1/0435/2986/3323/files/15797167167.pdf
    • https://cdn.shopify.com/s/files/1/0432/5038/5051/files/69051512702.pdf
    • https://cdn.shopify.com/s/files/1/0448/1345/1430/files/calendario_liturgico_2020_italiano.pdf
    • https://cdn.shopify.com/s/files/1/0432/7315/8806/files/notovugonowugiv.pdf
    • https://cdn.shopify.com/s/files/1/0431/3861/3415/files/35544784421.pdf
    • https://cdn.shopify.com/s/files/1/0430/9434/3841/files/lupiwijumawijosug.pdf
    • https://cdn.shopify.com/s/files/1/0431/0247/0306/files/neneleterofonenadovuvovir.pdf
    • https://cdn.shopify.com/s/files/1/0437/2247/3624/files/history_of_ancient_egypt_free_download.pdf
    • https://cdn.shopify.com/s/files/1/0427/7121/8588/files/fijidodefus.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00004e56.bin
2563ddeb4edd6b5386d53b515d791c33909addf002b5fb7157bb6db9a1975b72
pdf-font-stream PDF embedded font (sfnt) at offset 0x4E56 5624 bytes
font_01_sfnt_off00006182.bin
cf2ab647059e12d3483ee85da786aa2ec0281b7c331542e7ac553c74fa63e661
pdf-font-stream PDF embedded font (sfnt) at offset 0x6182 5456 bytes
font_02_sfnt_off0000730c.bin
9c7e5d2d2ec24d21cbb1c512bb7e015bd8f3232341a281d77cbf8744d3ec3786
pdf-font-stream PDF embedded font (sfnt) at offset 0x730C 10160 bytes