Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a1d528de77bd603…

MALICIOUS

PDF

67.1 KB Created: 2020-09-10 18:53:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d85acf42513a0afd6722c7dcabd5b5b1 SHA-1: 3fb98d898fff6138ca14365abf44e6ebccd89329 SHA-256: 8a1d528de77bd6036c3846303b31f2340502349c2fc9dfcb0155804f6c3821bd
152 Risk Score

Malware Insights

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

The PDF contains a link to a known malicious redirector, ttraff.link, disguised as a link to 'adverbs of degree worksheets pdf with answers'. This suggests a phishing or malware delivery attempt. The PDF also hosts a large number of external links, many pointing to static.usrfiles.com, indicating a potential link farm or SEO poisoning tactic to drive traffic to malicious sites. No scripts were extracted, but the presence of a malicious redirector and the ML classifier's high confidence score strongly indicate malicious intent.

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.link/wix?keyword=adverbs+of+degree+worksheets+pdf+with+answers
    • https://static.usrfiles.com/ugd/66c878_005d8fd37f4f4a8cbb6bb8007e02b6b5.pdf
    • https://static.usrfiles.com/ugd/5ecadc_6e06de8ea795488993e449d26326dbe8.pdf
    • https://static.usrfiles.com/ugd/9e53d4_2622286b313940b68add66a25e6e137d.pdf
    • https://static.usrfiles.com/ugd/bf650e_e69e8406fbb148bb8696fd5f2c57d689.pdf
    • https://static.usrfiles.com/ugd/665c20_081a5b500c9a4d18906bcbf76600d166.pdf
    • https://static.usrfiles.com/ugd/f103bb_d81bb2c7f0dc4202870f8a15d9751d41.pdf
    • https://static.usrfiles.com/ugd/34ec99_087eda7e3da4462aaae5d99edf8726a3.pdf
    • https://static.usrfiles.com/ugd/b8c837_ddbbd5f0e68a4e4d8a973a8d228d58dd.pdf
    • https://static.usrfiles.com/ugd/ae059d_93a2ef38f666418f993938cb46b51ee3.pdf
    • https://cdn.shopify.com/s/files/1/0463/5331/8054/files/aha_guidelines_endocarditis_prophylaxis.pdf
    • https://cdn.shopify.com/s/files/1/0440/1466/5886/files/janta_ki_adalat_hd_video_song.pdf
    • https://cdn.shopify.com/s/files/1/0434/9673/4885/files/vofaxi.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/
    • https://static.usrfiles.com/ugd/5ecadc_6e06de8ea7954

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bfe7.bin
85b692c1c636aed9ab1240d2a7361179fdd6c0849396a06064984f922e967b4f
pdf-font-stream PDF embedded font (sfnt) at offset 0xBFE7 2828 bytes
font_01_sfnt_off0000c9e1.bin
ad3453c33513f3764c1d2e5895619b6701b9be0595ffc96c17b4dfcff05546e3
pdf-font-stream PDF embedded font (sfnt) at offset 0xC9E1 5616 bytes
font_02_sfnt_off0000dd10.bin
6c057f7452ba7b81b52de78ca666505b13fe168d97f5fdc6c2e3488b9eac1299
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD10 9880 bytes