Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f840521ecb8ee65…

MALICIOUS

PDF

41.8 KB Created: 2020-08-30 22:48:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fcdaed476db9110afcc0a39979371678 SHA-1: 6b8a5352e0bb9d31a0b61d6aaa93e88fe4c5d941 SHA-256: 8f840521ecb8ee651938b2c0913b1aa2b95c53a03f7f71cdf01cf7b291e4207b
152 Risk Score

Malware Insights

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

The PDF was flagged by a critical heuristic for linking to known malicious redirector infrastructure. Additionally, another critical heuristic identified it as a PDF link farm containing numerous external links, with the primary suspicious URL being ttraff.ru. The ML classifier also strongly indicated maliciousness. The document body contains the suspicious URL and other PDF links, reinforcing the link farm attack pattern.

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=inteligencia+y+pensamiento
    • https://static.usrfiles.com/ugd/c83fdb_8e6b6c2a91094090859f3a3a41fa6354.pdf
    • https://static.usrfiles.com/ugd/79e0dc_ee520b1e14394bd3be326cae0a15217b.pdf
    • https://static.usrfiles.com/ugd/784815_884f0f2fccd745bda8a3a1fe69b32927.pdf
    • https://cdn.shopify.com/s/files/1/0430/3070/8375/files/tirofadalif.pdf
    • https://cdn.shopify.com/s/files/1/0431/2875/0241/files/osrs_smithing_guide_no_blast_furnace.pdf
    • https://cdn.shopify.com/s/files/1/0434/9604/6752/files/lefixulozugemetek.pdf
    • https://cdn.shopify.com/s/files/1/0431/2009/9488/files/80349342391.pdf
    • https://static.usrfiles.com/ugd/8b9728_22c2ea9c4b7e4c9d8f2c36838acb9b62.pdf
    • https://static.usrfiles.com/ugd/b8c837_5115728ce64343c68e1683551c93fbcf.pdf
    • https://static.usrfiles.com/ugd/b8c837_2f3eccaf156e4af7859294b9918a49ba.pdf
    • https://static.usrfiles.com/ugd/cf14a4_90a0280000324653888cdd9f796b769d.pdf
    • https://static.usrfiles.com/ugd/ca32a8_97a85723d4854bf9a856aef2b471ebb7.pdf
    • https://cdn.shopify.com/s/files/1/0461/2246/7492/files/41501062275.pdf
    • https://cdn.shopify.com/s/files/1/0440/6312/9765/files/96107384165.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_off00006355.bin
8f381659f022563e859edb62c9bd3f8ba153a0f425141a9c74ccd29a40e9e030
pdf-font-stream PDF embedded font (sfnt) at offset 0x6355 5196 bytes
font_01_sfnt_off000074fe.bin
4e81d5f44218a008b2f9421a8d0a258f223d70d1c4bf579bdea625d738a1431d
pdf-font-stream PDF embedded font (sfnt) at offset 0x74FE 11076 bytes