Malicious PDF — malware analysis report

Static analysis result for SHA-256 8df77cd02f6f1778…

MALICIOUS

PDF

44.2 KB Created: 2020-08-10 06:40:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cd629c990943487b911c2dde4d510b97 SHA-1: 8dbbac9629ffac0dfba890ab8290eb9fd646c4bc SHA-256: 8df77cd02f6f177810610ee622fd1660c6fd1e69b7a985b79bca8bbc2891a70a
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 redirecting to a known malicious infrastructure. The document body, though heavily obfuscated, contains the same URL and keywords suggesting a lure for users to download a dictionary, which is a common social engineering tactic. 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.cc/pify?keyword=merriam+webster+advanced+learner+english+dictionary+free+download+pdf
    • http://files.stealthbrew.co/uploads/1/3/0/7/130738572/5595438.pdf
    • http://bomep.lyoneyecosmetic.com/uploads/1/3/1/6/131636725/jexoresefisuvit_xusowe_xugejaxilugi.pdf
    • http://files.ak4h.org/uploads/1/3/1/8/131871814/08e0f7a.pdf
    • http://kuroke.megan-livingston.com/uploads/1/3/2/7/132741334/16ee756345.pdf
    • https://cdn.shopify.com/s/files/1/0430/4617/4877/files/81792605891.pdf
    • https://cdn.shopify.com/s/files/1/0429/2493/3287/files/20022530720.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/58863311498.pdf
    • https://cdn.shopify.com/s/files/1/0431/6617/1287/files/rimekidejojatagolin.pdf
    • https://cdn.shopify.com/s/files/1/0431/1960/7965/files/wotumimoxodim.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/83406059157.pdf
    • https://cdn.shopify.com/s/files/1/0428/8207/2732/files/vepajulax.pdf
    • https://cdn.shopify.com/s/files/1/0434/4738/6264/files/renutatox.pdf
    • https://cdn.shopify.com/s/files/1/0428/3046/3142/files/nopikadisukifelod.pdf
    • https://cdn.shopify.com/s/files/1/0431/2881/5783/files/paleo_diet_food_plan.pdf
    • https://cdn.shopify.com/s/files/1/0432/6129/6790/files/41087937789.pdf
    • https://cdn.shopify.com/s/files/1/0431/2032/8864/files/tamajusofogukajibola.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_off00006b22.bin
bf5f0218bc951e0e53a73d6513d21f51594985c9189a67139c9629e8ff9bc305
pdf-font-stream PDF embedded font (sfnt) at offset 0x6B22 5968 bytes
font_01_sfnt_off00007f6e.bin
1591a607dd063654375b3198bfca07221da0d42e65dd291f75e2fa8418b06efa
pdf-font-stream PDF embedded font (sfnt) at offset 0x7F6E 10444 bytes