Malicious PDF — malware analysis report

Static analysis result for SHA-256 81dc37990e4fabfe…

MALICIOUS

PDF

40.9 KB Created: 2020-08-29 14:38:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1f2189833f87bdcd645aadab7db1fb1f SHA-1: ef9302112d7d2a84924a8185372ba29fe1f6ca84 SHA-256: 81dc37990e4fabfebfbab6b0e8b5e90e429f954c35dc57c247a1eaa82cb97c69
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious due to embedded links pointing to known malicious redirector infrastructure. The primary URL identified is 'https://ttraff.ru/wix?keyword=caracteristicas+de+una+columna+de+op', which is a critical finding. Additionally, the file contains a large number of external PDF links, many hosted on 'static.usrfiles.com', suggesting a link farm or redirection strategy. 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.ru/wix?keyword=caracteristicas+de+una+columna+de+op
    • https://static.usrfiles.com/ugd/c12414_75b118ecf3cc4e23b3588d709dc1f30a.pdf
    • https://static.usrfiles.com/ugd/b8c837_1e32c33576144ae6bc827d11eab69f72.pdf
    • https://static.usrfiles.com/ugd/b8c837_8470ae7d1d0b452a93a2c3e5dfdec204.pdf
    • https://cdn.shopify.com/s/files/1/0435/5696/2465/files/introduction_to_electrodynamics_griffiths.pdf
    • https://cdn.shopify.com/s/files/1/0430/1615/9385/files/93179734805.pdf
    • https://cdn.shopify.com/s/files/1/0435/3762/9348/files/zogibefeludonuwifut.pdf
    • https://static.usrfiles.com/ugd/b8c837_4b28dbd51aa849438d16c2af0ff31a96.pdf
    • https://static.usrfiles.com/ugd/b8c837_01abae187c814641bd7c5b67a3d3278f.pdf
    • https://static.usrfiles.com/ugd/b8c837_117d75b6444e4070a4938bab2526fbed.pdf
    • https://static.usrfiles.com/ugd/b8c837_da99e3eadee44d1e975eaa4469a1a355.pdf
    • https://static.usrfiles.com/ugd/b8c837_b8df395f89ca44448552ca8b3ca96768.pdf
    • https://cdn.shopify.com/s/files/1/0431/5031/1579/files/dinobotepejibawesetosi.pdf
    • https://cdn.shopify.com/s/files/1/0428/9773/5843/files/80369476870.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/baludugosutagaxoreforodul.pdf
    • https://cdn.shopify.com/s/files/1/0433/5583/2471/files/rorulodaxudoj.pdf
    • https://cdn.shopify.com/s/files/1/0431/6063/3504/files/ziziwabi.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_off00005eee.bin
718bd436d0ac73d51d117acfb2aaa7bde9e9ddcf11e09dc2bd7114206a7989e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x5EEE 5124 bytes
font_01_sfnt_off00007039.bin
c1c2e4a71d9da57e5e51fe03ee85591efd9cf8c4082229fdee0b5507c1745032
pdf-font-stream PDF embedded font (sfnt) at offset 0x7039 11392 bytes