Malicious PDF — malware analysis report

Static analysis result for SHA-256 b31731a8f0d9f279…

MALICIOUS

PDF

39.9 KB Created: 2020-08-22 20:06:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1fd2c44f8873c5c3f46a757b73760297 SHA-1: 5adcf3143a8a8fea8c708d781943ffcbaccf1fc9 SHA-256: b31731a8f0d9f279d57963c27a6b2a82302a7e3c753cf5e7e6a26b270b675c09
152 Risk Score

Malware Insights

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

The PDF contains a malicious redirector link that leads to a farm of other PDF links, likely for SEO manipulation or to host further malicious content. The ML classifier strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains the primary malicious URL and references to other benign-looking PDFs hosted on Shopify, suggesting a lure to a more dangerous destination.

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.cc/pify?keyword=simple+present+tense+worksheet+for+class+4th
    • http://files.tomfieldinggolf.net/uploads/1/3/0/8/130874023/gewovebotimegi.pdf
    • http://gatabun.aim-na.org/uploads/1/3/0/8/130814328/1938629.pdf
    • http://volisi.edgewaterva.com/uploads/1/3/2/6/132681501/60ea0e960.pdf
    • http://mizim.leahchang.ca/uploads/1/3/2/3/132303052/bivasuk-febuw-dunedabu-pupoxi.pdf
    • https://cdn.shopify.com/s/files/1/0441/0392/5912/files/banking_and_financial_awareness_2020.pdf
    • https://cdn.shopify.com/s/files/1/0435/6934/8763/files/90814073126.pdf
    • https://cdn.shopify.com/s/files/1/0453/8272/9896/files/bartender_enterprise_automation_software.pdf
    • https://cdn.shopify.com/s/files/1/0434/3824/3996/files/libro_los_12_economistas_mas_importantes_de_la_historia.pdf
    • https://cdn.shopify.com/s/files/1/0434/0839/2353/files/4_branches_of_military_uniforms.pdf
    • https://cdn.shopify.com/s/files/1/0428/5415/4406/files/aao_na_lyrics.pdf
    • https://cdn.shopify.com/s/files/1/0429/6802/3194/files/lizorafe.pdf
    • https://cdn.shopify.com/s/files/1/0427/6148/6503/files/55520392942.pdf
    • https://cdn.shopify.com/s/files/1/0428/7696/0924/files/mutulibojaf.pdf
    • https://cdn.shopify.com/s/files/1/0437/9492/3677/files/xutugorejik.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_off00005be0.bin
b45756eac6f67eb9bb185bf87d84b85d4351becd1373862b03234fdc0e03b847
pdf-font-stream PDF embedded font (sfnt) at offset 0x5BE0 5604 bytes
font_01_sfnt_off00006ed1.bin
263bbd206aa7e3bbb5653e2e04862fc1a91cea7ad1ab32c86a26dc082813099d
pdf-font-stream PDF embedded font (sfnt) at offset 0x6ED1 10552 bytes