Malicious PDF — malware analysis report

Static analysis result for SHA-256 55dbf50d210c5807…

MALICIOUS

PDF

33.2 KB Created: 2020-08-29 14:59:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d32c8ea0a1c3db22bbd268eb15a9417d SHA-1: cef625a1bfb6f970b42524a4935c785d4c0dd706 SHA-256: 55dbf50d210c5807a360ac0dea966746ff9ec2e09578b6ad8b9148dffd4bf039
152 Risk Score

Malware Insights

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

The PDF contains a mass external link farm, with the primary link pointing to a known malicious redirector. The document body, though partially corrupted, includes text suggesting a lure for a free download, which is consistent with the observed link farm behavior. The ML classifier 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=chemical+technicians+ready+reference+handbook+free+download
    • https://static.usrfiles.com/ugd/b8c837_c808b6b09c1e45648afa93b61cb4a8ea.pdf
    • https://static.usrfiles.com/ugd/0a0016_1f048a7cd9d648ecbbaedf9c490c9dc8.pdf
    • https://static.usrfiles.com/ugd/b8c837_e3c5f7b5177842d1a8af5e3d7de42d29.pdf
    • https://static.usrfiles.com/ugd/b8c837_af2cee9a670f4813b69f73cfc40e8136.pdf
    • https://cdn.shopify.com/s/files/1/0429/2801/3475/files/mifiwuriviruposukozujabi.pdf
    • https://cdn.shopify.com/s/files/1/0431/9540/0356/files/27841466436.pdf
    • https://cdn.shopify.com/s/files/1/0428/0667/3574/files/6132408921.pdf
    • https://cdn.shopify.com/s/files/1/0433/7818/0257/files/wanajopamasezuxoremozidim.pdf
    • https://cdn.shopify.com/s/files/1/0431/4628/1120/files/rac_breakdown_cover_uk_policy_booklet.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/24221046066.pdf
    • https://cdn.shopify.com/s/files/1/0429/1015/4908/files/monubawolebojeno.pdf
    • https://cdn.shopify.com/s/files/1/0437/4301/9159/files/armatures_standard_bton_arm.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/52665001447.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_off000044bd.bin
7b2c67181a51298d02465090e13d35d471fcd8b605705b629de36b2420256c07
pdf-font-stream PDF embedded font (sfnt) at offset 0x44BD 5564 bytes
font_01_sfnt_off00005788.bin
e9f53118c7a61640377936f63e5a07cc77987e623594cb14c066b1d91415025f
pdf-font-stream PDF embedded font (sfnt) at offset 0x5788 9464 bytes