Malicious PDF — malware analysis report

Static analysis result for SHA-256 c0a012ca8b380ca8…

MALICIOUS

PDF

40.3 KB Created: 2020-08-14 11:54:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f7cc9fd48be3ff7df0a41d5e074ff27a SHA-1: e4bc3f77a3126132f94567b0744e50a9c2d8abde SHA-256: c0a012ca8b380ca84ae1848ae40797e1d067ba237062e80f37ee904d4ac95289
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many pointing to Shopify domains, which is indicative of a link farm. One of the primary links, 'https://ttraff.ru/wb?keyword=hsk%20level%201%20exam%20pdf', is flagged as a malicious redirector. The document body, though heavily obfuscated, contains references to 'hsk level 1 exam pdf', suggesting a lure to entice users to click on the malicious links.

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/wb?keyword=hsk%20level%201%20exam%20pdf
    • http://files.villaamizade.com/uploads/1/3/1/1/131164016/7784208.pdf
    • http://files.mx.cbisociety.org/uploads/1/3/0/7/130776055/d4666a.pdf
    • http://vudubuw.ryandawalt.com/uploads/1/3/1/6/131606577/fananexinagomis-levejovaf.pdf
    • https://cdn.shopify.com/s/files/1/0431/2681/6932/files/waxojijosirupe.pdf
    • https://cdn.shopify.com/s/files/1/0447/4827/5863/files/cement_forming_boards.pdf
    • https://cdn.shopify.com/s/files/1/0435/7577/1304/files/fojopisovimeworefagu.pdf
    • https://cdn.shopify.com/s/files/1/0428/5346/6271/files/nonemotere.pdf
    • https://cdn.shopify.com/s/files/1/0431/2743/9526/files/lomiduzabi.pdf
    • https://cdn.shopify.com/s/files/1/0433/3276/3801/files/26406681522.pdf
    • https://cdn.shopify.com/s/files/1/0435/6007/5427/files/12065476733.pdf
    • https://cdn.shopify.com/s/files/1/0432/5956/0086/files/16527052713.pdf
    • https://cdn.shopify.com/s/files/1/0434/4535/4658/files/writing_academic_english_pearson_longman.pdf
    • https://cdn.shopify.com/s/files/1/0428/8220/3801/files/bass_guitar_scales_for_beginners.pdf
    • https://cdn.shopify.com/s/files/1/0432/5192/5155/files/kolemo.pdf
    • https://cdn.shopify.com/s/files/1/0433/1054/7099/files/31152441036.pdf
    • https://cdn.shopify.com/s/files/1/0439/8622/3262/files/durijasawovefuwi.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_off00005ee0.bin
80fdf98e192b3b5d9d25c587197b8232d5e8b5d79730327e4bef29ede04af06b
pdf-font-stream PDF embedded font (sfnt) at offset 0x5EE0 5296 bytes
font_01_sfnt_off000070e5.bin
e59a91fc0547fddd12b8a5ec2836b35eeb1ee36573a47969e647a9503732151b
pdf-font-stream PDF embedded font (sfnt) at offset 0x70E5 10432 bytes