Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4bf8c860e45a9ec…

MALICIOUS

PDF

40.7 KB Created: 2020-09-01 20:02:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cbd3fc7fb4f4bfe08536e129b8648ecd SHA-1: 0fcfaefce0b17d306de6684685cb76d91db71582 SHA-256: a4bf8c860e45a9ec49cc36a8b15fa31e8f9918538d2b712a45d53ee70da8c6b3
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic firing indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains the URL https://ttraff.ru/wix?keyword=bully+size+kecil+android, which is likely intended to lure the user to a malicious site. The ML classifier also strongly flagged this PDF as malicious.

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=bully+size+kecil+android
    • https://static.usrfiles.com/ugd/b8c837_45f32cf3ec2948f5b6d9871cdedec016.pdf
    • https://static.usrfiles.com/ugd/253000_3f53f8fd4ce14d4fabced868c004c23f.pdf
    • https://static.usrfiles.com/ugd/868401_b45cf1272c954bf58cf801fcc25f4505.pdf
    • https://static.usrfiles.com/ugd/b3bc21_9125cd3c968149f387390f6d5726dcec.pdf
    • https://static.usrfiles.com/ugd/49be48_6c602f4418fb4b72a8b221802b0dde5c.pdf
    • https://cdn.shopify.com/s/files/1/0433/2702/9400/files/lp_antepartum_bleeding.pdf
    • https://static.usrfiles.com/ugd/b8c837_6ea50097fd1344778fc09c232cb3b066.pdf
    • https://static.usrfiles.com/ugd/aff7ca_0a58d66cdf8f4864b9bcbe3823ac8e03.pdf
    • https://static.usrfiles.com/ugd/b8c837_12a2c83f2b20499789281d00ed5d31f4.pdf
    • https://static.usrfiles.com/ugd/90423f_a41fa735e1de4a4683e9a6f25b094ac6.pdf
    • https://static.usrfiles.com/ugd/d902bb_344851f27e0049e5a2878ea546dc8e56.pdf
    • https://static.usrfiles.com/ugd/23e9be_262917df66844ea1b48200f11262a729.pdf
    • https://static.usrfiles.com/ugd/4b874d_6b98eb7e683344cca8698df32a552515.pdf
    • https://static.usrfiles.com/ugd/07625c_0c33e273750e4963af2afbe739383b08.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_off000060b7.bin
55ccbb8fe9334c938f525159af749b297d860594a3e25667a43fea0d4350eb3f
pdf-font-stream PDF embedded font (sfnt) at offset 0x60B7 5196 bytes
font_01_sfnt_off0000728c.bin
0737755fae67308c1af3f7c840ac6e6de1861185dfd2513e22f11a3686ff31fc
pdf-font-stream PDF embedded font (sfnt) at offset 0x728C 10456 bytes