Malicious PDF — malware analysis report

Static analysis result for SHA-256 6680f39c082b2bad…

MALICIOUS

PDF

54.1 KB Created: 2020-08-14 20:26:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 45e1cefd030ccb36026ed5c63754b6df SHA-1: cfc6de9ef2118f8315486700adee81d7b34874cd SHA-256: 6680f39c082b2bad6d12843938e210ca2dd42440bfda3b1b0f96676903f2eadd
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a link that redirects to a known malicious infrastructure, disguised with text related to GRE arithmetic questions. The document also hosts a large number of external PDF links, many of which are benign, but the primary redirector is highly suspicious. The ML classifier also strongly indicated maliciousness.

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=gre+arithmetic+questions+and+answers
    • http://files.sarayaharon.com/uploads/1/3/1/6/131606186/bfabe2e382fc.pdf
    • http://files.theknitknits2.com/uploads/1/3/0/7/130739895/gokaxap-pofimaluwokal.pdf
    • http://files.greatcowbasic.com/uploads/1/3/1/4/131407974/22648aad.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0450/8942/3525/files/it2301_java_programming_notes.pdf
    • https://cdn.shopify.com/s/files/1/0438/2025/3344/files/fugukajaxupuz.pdf
    • https://cdn.shopify.com/s/files/1/0434/5551/2738/files/concept_of_state_in_political_science.pdf
    • https://cdn.shopify.com/s/files/1/0429/4528/2214/files/61930922709.pdf
    • https://cdn.shopify.com/s/files/1/0435/0682/7428/files/24683876089.pdf
    • https://cdn.shopify.com/s/files/1/0434/6288/5541/files/72818051409.pdf
    • https://cdn.shopify.com/s/files/1/0436/1447/0302/files/tivevewejufemer.pdf
    • https://cdn.shopify.com/s/files/1/0431/1046/5698/files/67539385740.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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007df6.bin
f236596a80ac99ea6de34737b168b948f7bd6c897f6484dee7eb6b086fa440ce
pdf-font-stream PDF embedded font (sfnt) at offset 0x7DF6 5396 bytes
font_01_sfnt_off00009039.bin
d6fb37d53db1cc893f2d95ba4cfb8b19a3454c23a7d233685aed199a4f391e4b
pdf-font-stream PDF embedded font (sfnt) at offset 0x9039 10872 bytes
font_02_sfnt_off0000b561.bin
cc9618900e256a39069df4d65f1d540b234ab68123a8689fe770a3579ee18932
pdf-font-stream PDF embedded font (sfnt) at offset 0xB561 16236 bytes